U  F 


No.  1705 


INSTRUCTIONS  FOR  MOUNTING, 
USING,  AND  CARING  FOR 

MORTAR  CARRIAGES 

MODEL  OF  1  896  Ml 
AND  MODEL  OF  1  896  Mil 

FOR 

12-INCH  MORTARS 

MODEL  OF  1890  Ml 


IRLF 


(TWELVE  PLATES] 


APRIL  22,  1909 
REVISED  MARCH  18,  1913 
REVISED  JANUARY  11, 1916 


ro 


o 


WASHINGTON 

GOVERNMENT  PRINTING  OFFICE 
1917 


GIFT   OF 


So.  17O5 

"ty.S.   Oret*\  9  ^  ce-      i?(e|»i". 

INSTRUCTIONS  FOR  MOUNTING, 
USING,  AND  CARING  FOR 

MORTAR  CARRIAGES 

MODEL  OF  1 896  Ml 
AND  MODEL  OF  1896  Mil 

FOR 

12-INCH  MORTARS 

MODEL  OF  1890  Ml 


(TWELVE  PLATES} 


APRIL  22,  1909 
REVISED  MARCH  18,  1913 
REVISED  JANUARY  11, 1916 


WASHINGTON 

GOVERNMENT  PRINTING  OFFICE 
1917 


WAR  DEPARTMENT, 
OFFICE  OF  THE  CHIEF  OF  ORDNANCE, 

Washington,  January  11,  1916. 

This  manual  is  published  for  the  information  and  government  of  the  Regular  Army 
and  Organized  Militia  of  the  United  States. 
By  order  of  the  Secretary  of  War: 

WILLIAM  CROZIER, 
Brigadier  General,  Chief  of  Ordnance . 

(3) 


366527 


TABLE  OF  CONTENTS. 


Page. 

Action  of  carriage 9 

Adjustment  of  springs 23 

Assembling  the  carriage 19 

Azimuth  circle 24 

Azimuth  circle  and  pointer 15 

Base  ring 10,  20 

Care  of  the  carriage — general  instructions 25 

Cleaning  recoil  cylinders 26 

Compression  grease  cups ^ 28 

Counter-recoil  springs 22 

Counter-recoil  springs  and  buffer  stops 13 

Distance  rings  and  traversing  rollers 21 

Electrical  attachments 16 

Elevating  gear 23 

Elevating  system 13 

Elevation  quadrant 15 

Emplacement 9 

Filling  recoil  cylinders 27 

Floor  plate,  ladder,  and  dust  guards 21 

General  description 9 

General  remarks 19 

Important  points 24 

Implements 19 

Lanyard  attachment 16 

Leveling ....-_ 20 

List  of  plates 7 

Oil  holes ...., 28 

Principal  parts 10 

Racer 21 

Racer  and  side  frames 10 

Recoil  cylinders 22 

Recoil  system 11 

Removing  packing  from  stuffing  boxes 26 

Service  condition  (lubrication,  etc.) 27 

Shot  trucks  and  shot  tongs 19 

The  carriage 9 

To  connect  the  piece  with  the  recoil  system 23 

To  dismount  carriage  for  purpose  of  cleaning  trunnions  and  springs 25 

To  lower  the  piece 23 

To  mount  the  mortar  by  blocking 22 

To  pack  a  stuffing  box 27 

To  remove  cradle  and  track 22 

Top  carriage 22 

Tools  and  accessories  and  implements 19 

Traversing  mechanism 24 

Traversing  roller  system 10 

Traversing  system 15 

(5) 


LIST  OF  PLATES. 


MORTAR  CARRIAGE,  MODEL  OF  1896  Mi. 

Drawing  No . 

I .  Emplacement 15-12K-2 

II.  General  drawing • 12-12-1 

III.  Elevating  gear ; 15-12K-8 

IV.  Traversing  gear 12-12-14 

V.  Recoil  cylinder 12-12-18 

VI.  Shot  truck. 15-12K-15 

VII.  Wiring  diagram 12-12-21 

MORTAR  CARRIAGE,  MODEL  OF  1896  Mn. 

I.  Emplacement , . .  15-12K-2 

VIII.  Longitudinal  section 12-13-1 

IX.  Rear  elevation ." 12-13-2 

III.  Elevating  gear 15-12K-8 

X.  Traversing  gear 12-13-8 

XI .  Recoil  cylinder  and  guides 12-13-7 

VI.  Shot  truck 15-12K-15 

XII.  Wiring  diagram 12-13-11 

(7) 


INSTRUCTIONS 


FOR 


MOUNTING,  USING,  AND  CARING  FOR  MORTAR  CAR- 
RIAGES, MODEL  OF  1896  Mi  AND  MODEL  OF  1896  Mn, 
FOR  12-INCH  MORTARS,  MODEL  OF  1890  ML 


TWELVE  PLATES. 


(The  points  in  italics  are  of  importance  and  should  be  specially  noted.) 
GENERAL   DESCRIPTION. 

NOTE. — The  general  designs  of  the  two  mortar  carriages,  model  of 
1896  Mi  and  1896  Mil,  are  very  similar,  the  changes  incorporated  in 
the  later  model  being  mainly  in  the  line  of  greater  strength.  The 
instructions  below  apply  to  both  models  of  carriages  unless  otherwise 
indicated. 

THE  EMPLACEMENT  (Plate  I). — This  emplacement  is  constructed 
of  concrete,  the  loading  platform  of  which  is  flush  with  the  top 
surface  of  the  floor  plates  of  carriage  when  it  is  assembled.  It  con- 
tains a  circular  well  59.5  inches  deep  with  steps  on  which  the  base 
ring  is  supported.  The  edge  of  the  loading  platform  is  not  com- 
pleted until  the  angle  irons  which  support  the  azimuth  circle  and 
floor  plates  have  been  located  and  their  curved  ends  embedded  in 
the  concrete.  The  anchor  bolts  are  also  embedded  in  the  concrete 
when  the  emplacement  is  constructed. 

THE  CARRIAGE  (Plate  II). — This  carriage  is  designed  to  deliver  an 
all-round  high-angle  fire  of  from  45°  to  70°  elevation. 

With  the  1,046-pound  projectile  and  full  charge,  the  recoil  is 
approximately  23  inches,  measured  on  the  piston  rods. 

The  horizontal  piece  when  fully  counter-recoiled  is  54  inches 
above  the  loading  platform,  and  the  projectile,  in  loading,  is  wheeled 
directly  into  the  breech  recess,  the  tray  of  the  ammunition  trucks 
forming  the  loading  tray. 

ACTION  OF  CARRIAGE. — Upon  firing,  the  piece  and  top  carriage 
rotate  to  the  rear  and  downward  about  the  fulcrum  pins,  compressing 
9977—17 2  (9) 


10 

the  counter-recoil  springs  ai^d  forcing  the  crossheads  and  pistons 
downward,  until  tlu-  ^orabmed,  resistance  in  the  recoil  cylinders  and 
the  springs  stop  the  motion,  after  which  the  compressed  counter-recoil 
springs  immediately  return  the  piece  to  the  loading  and  firing  height. 
The  movement  of  the  crank  pin  through  the  arc  of  a  circle  causes  the 
recoil  cylinders  and  guides  to  oscillate  about  their  trunnions. 

PRINCIPAL  PARTS. — The  carriage  consists  of  the  following  principal 
parts,  viz:  Base  ring  and  floor  plates,  traversing  roller  system,  racer, 
side  frames,  top  carriage,  recoil  system,  counter-recoil  springs  and 
buffer  stops,  elevating  gear,  traversing  gear,  azimuth  circle  and 
pointer,  elevation  quadrant,  lanyard  attachment,  electrical  equip- 
ment, shot  trucks,  shot  tongs,  tools  and  accessories,  and  implements. 

BASE  RING. — The  base  ring  is  of  cast  iron,  in  one  piece,  and  is 
secured  in  its  position  by  twenty-four  1.75-inch  anchor  bolts.  The 
outer  flange  of  the  base  ring,  14  feet  in  diameter,  which  contains 
the  bolt  holes,  rests  upon  the  upper  step  of  the  well,  whose  surface 
is  24.5  inches  below  the  floor  level  of  the  emplacement. 

The  top  surface  is  turned,  forming  the  lower  roller  path  and  a 
vertical  annular  flange  forms  the  male  part  of  the  pintle.  The 
traversing  rack  is  attached  on  the  inside  below  the  roller  path,  and 
its  upper  and  lower  surfaces  are  turned,  forming  the  brake  path. 

Eight  brackets,  rigidly  supporting  the  azimuth  circle  castings, 
are  bolted  to  the  outer  flange,  these  brackets  and  castings,  together 
with  radial  angle  irons  whose  outer  ends  are  embedded  in  the  con- 
crete, furnishing  the  support  for  the  circle  of  cast-iron  removable 
floor  plates.  There  are  16  plates,  retained  in  position  by  countersunk 
screws. 

TRAVERSING  ROLLER  SYSTEM. — The  racer  rests  and  is  traversed 
upon  a  circle  of  24  live,  conical,  traversing  rollers  of  forged  steel, 
with  a  single  flange.  The  rollers  are  7.5  inches  in  maximum  diameter, 
and  their  axes  are  held  in  the  radial  position  by  a  wrought-iron 
(cast  steel  in  some  carriages)  distance  ring  in  six  sections,  in  which 
their  bronze-bushed  journals  have  bearings.  The  distance  ring 
has  oil  grooves  finished  around  its  top  edges,  reached  through  oil 
tubes  in  racer. 

RACER  AND  SIDE  FRAMES. — The  racer  of  the  model  of  1896  Mi 
carriage  is  cast  in  one  piece,  13  feet  9.5  inches  in  diameter.  Its 
tower  surface  is  turned,  forming  the  upper  roller  path,  corresponding 
to  the  lower  roller  path  on  the  base  ring.  The  outside  annular 
flange  extends  downward,  fitting  over  the  pintle  with  0.063  inch 
diametral  clearance.  It  is  a  cellular  structure,  and  upon  its  front 
edge  are  cast  two  lugs  or  brackets  to  which  the  top  carriage  is  pivoted 
by  means  of  steel  fulcrum  pins.  On  each  side  of  the  central  opening 
are  side  frames  running  across  to  the  racer  from  front  to  rear.  These 


11 

side  frames  form  the  supporting  bearings  for  the  recoil  cylinders 
and  also  for  the  fulcrum  pins.  Three  removable  oil  plugs  permit 
oiling  the  pintle  and  traversing  rollers. 

Cast  iron  was  originally  specified  as  the  material  for  the  racer,  and 
most  of  the  carriages  in  service  have  racers  of  that  material.  As  a 
result  of  the  cracking  of  several  of  these  racers,  cast  steel  No.  2  is 
now  specified,  and  all  racers  hereafter  manufactured  will  be  of  this 
material. 

(NOTE. — The  cast-iron  racers  of  carriages  Nos.  104,  106,  116, 
125,  148,  150,  151,  158,  165,  193,  209,  210,  237,  241,  243,  244, 
260,  261,  262,  289,  294,  and  300  have  already  been  replaced  by 
cast-steel  racers.) 

A  few  of  the  cast-iron  racers  have  been  strengthened  by  the  addi- 
tion of  reinforcing  plates  of  steel  placed  along  the  vertical  sides  of 
the  central  opening. 

The  racer  for  the  model  of  1896  Mn  carriage  is  cast  with  two  longi- 
tudinal ribs,  one  on  each  side  of  the  central  opening.  These  ribs 
correspond  to  the  side  frames  of  the  model  of  1896  Mi  carriage, 
reinforcing  the  racer  and  forming  bearings  for  the  cylinder  trun- 
nions. All  the  racers  of  this  model  carriage  are  of  cast  steel  No.  1. 

TOP  CARRIAGE. — The  top  carriage  consists  of  two  arms  connected 
by  a  heavy  web.  The  upper  ends  of  these  arms,  form  the  trunnion 
beds  in  which  the  mortar  is  mounted.  The  top  carriage  is  inclined 
to  the  rear  at  an  angle  of  about  41°,  the  lower  ends  being  held  by 
the  fulcrum  pins.  Between  the  fulcrum  and  the  trunnions  are 
placed  openings  for  the  spring  guide  rods  and  the  seat  for  the  rocking 
counter-recoil  spring  cap. 

All  model  of  1896  Mi  carriages,  except  Nos.  116,  125,  148,  149,  150, 
160,  176,  204,  211,  216,  251,  254,  255,  260,  262,  283,  289,  and  all 
model  of  1896  Mn  carriages  have  the  "Cast  steel  No.  2"  top  carriage 
shown  on  Plate  I.  The  except ed  carriages  have  steel-top  carriages 
of  an  older  pattern. 

RECOIL  SYSTEM. — The  recoil  is  checked  by  two  hydraulic  cylinders 
provided  with  trunnions  which  oscillate  in  their  beds  on  the  side 
frames,  their  lower  ends  extending  some  distance  below  the  racer. 
They  are  of  cast  steel,  7.78  inches  interior  diameter,  and  are  fitted 
with  3.5-inch  forged  steel  piston  rods  working  through  stuffing  boxes 
at  both  ends  of  the  cylinders.  About  the  middle  of  the  rod  is  screwed 
and  pinned  a  bronze  piston.  The  stuffing  boxes  each  contain  six 
rings  of  0.625  inch  square  Garlock  waterproof  hydraulic  packing. 
In  the  walls  of  each  cylinder  are  cut  three  grooves,  each  4.6892  inches 
in  width  and  of  varying  depth,  so  as  to  give  a  constant  pressure 
in  the  cylinders  during  the  entire  length  of  recoil.  The  energy  of 


12 

recoil  is  taken  up  by  the  resistance  which  the  fluid  offers  to  being 
driven  through  these  openings. 

NOTE. — The  by-pass  channels  and  openings  provided  in  model 
of  1896  Mi  mortar  carriages  are  not  now  used,  all  holes  opening 
into  the  by-pass  channels  being  plugged.  (Plate  V.)  The  cylin- 
ders of  model  of  1896  Mil  carriages  are  cast  without  provision 
for  by-pass  channel  and  openings. 

The  counter  recoil  is  checked  by  a  counter-recoil  buffer.  In  the 
model  of  1896  Mi  carriages  the  upper  face  of  each  piston  has  an 
annular  recess,  which  at  the  end  of  the  counter  recoil  passes  over 
the  annular  projection  on  buffer  on  the  upper  bronze  cylinder  head. 
The  fluid  thus  imprisoned  is  able  to  escape  by  the  clearances  only,  its 
resistance  gradually  checks  the  movement,  and  consequently  the 
mortar  returns  gently  to  the  firing  position.  In  the  model  of  1896 
Mil  carriages  the  male  part  of  the  buffer  is  on  the  piston  and  the 
female  part  on  the  cylinder  head,  the  principle  being  generally  similar 
to  that  described  above. 

The  filling  holes  are  now  located  about  the  middle  of  the  cylinders 
in  order  to  obtain  a  void,  and  the  oil  holes  on  the  rear  side  of  the 
cylinders  near  the  upper  ends  are  permanently  closed  and  can  not  be 
opened. 

For  all  charges  the  cylinders  should  be  filled  to  the  level  of  the  filling 
holes,  removing  for  this  purpose  both  plugs,  so  as  to  permit  the  air  to 
escape. 

A  neutral  oil,  of  specific  gravity  of  about  0.85  (such  as  the  "  Hydro- 
line"  at  present  issued),  is  used,  and  with  this  oil  the  working  pressure 
in  the  cylinders  is  about  5,000  pounds  per  square  inch  and  the  piston 
rod  compression  about  190,000  pounds.  A  denser  oil  would  cause  a 
higher  pressure  in  the  cylinders  and  therefore  shorten  the  recoil 
slightly. 

If  it  is  desired  to  measure  the  recoil,  it  can  be  done  on  one  of  the 
piston  rods  by  making  several  turns  around  it  with  fine  twine  and 
tying  it  tightly  just  where  the  piston  rod  enters  the  stuffing  box. 
The  height  of  the  twine  above  the  stuffing  box,  after  firing,  will  indi- 
cate the  counter  recoil,  which  will  also  be  the  recoil  if  the  mortar  has 
returned  to  the  firing  position.  If  it  does  not  return  to  the  firing 
position,  the  counter-recoil  springs  should  be  compressed. 

The  lower  ends  of  the  hydraulic  cylinders  are  connected  by  an 
equalizing  pipe,  in  which  is  made  up  an  emptying  coupling,  so  that 
the  resistance  and  the  pressure  in  both  cylinders  shall  be  equal.  The 
coupling  is  provided  for  emptying  the  cylinders  at  a  convenient  point. 

The  emptying  coupling  was  originally  made  of  bronze.  These  are 
being  replaced  by  steel  couplings  as  becomes  necessary. 


Bronze  plugs  are  provided  which  can  be  used  to  replace  the  equal- 
izing pipes,  thus  continuing  the  piece  in  action  after  their  injury. 

To  the  top  of  each  cylinder  are  bolted  two  guides  of  cast  steel, 
between  which  moves  a  sliding  crossnead,  into  which  the  upper  end 
of  the  piston  rod  is  secured  by  means  of  a  collar  ar.d  nut.  The  cross- 
heads  are  assembled  over  the  crank  pins,  of  forged  steel,  which  are 
screwed  into  the  trunnions  of  the  mortar  and  held  by  spline  screws. 

COUNTER-RECOIL  SPRINGS  AND  BUFFER  STOPS. — The  top  carriage 
is  supported  at  a  point  about  one-third  of  its  length  from  the  fulcrum 
shaft  by  five  columns  of  springs.  Each  column  consists  of  five 
double-coil  helical  springs,  threaded  on  a  rod  of  forged  steel.  These 
five  rods,  arranged  in  a  row  side  by  side,  serve  to  guide  the  springs 
laterally  during  recoil  or  counter  recoil.  They  are  also  used  to  sus- 
tain the  force  of  the  springs  when  the  mortar  is  dismounted  tem- 
porarily— the  spring  compressors  assisting. 

For  the  latter  purpose  the  spring-compressor  washers  are  placed 
over  the  spring-compressor  screws  and  the  latter  screwed  into  the 
ends  of  the  rods  (the  plugs  having  been  removed),  after  which  the 
spring-compressor  nuts  are  screwed  down  against  the  washers,  until 
the  crossheads  are  moved  a  short  distance  from  the  buffer  plates. 

The  lower  ends  of  these  spring  columns  rest  in  a  spring  box  of 
cast  iron  and  the  upper  ends  bear  against  a  spring  cap.  The  spring 
box  is  hung,  by  means  of  trunnions,  in  two  brackets  of  cast  iron 
bolted  to  the  under  surface  of  the  racer,  which  permit  it  to  oscillate 
during  recoil  to  the  different  inclinations  of  the  spring  columns. 
The  spring  cap,  performing  essentially  the  same  office  above  as  the 
spring  box  does  below,  is  a  thin  rectangular  steel  casting  fitting  over 
the  top  of  the  spring  columns,  and  having  upon  its  upper  surface  a 
well-rounded  knife-edge  bearing.  During  recoil  this  bearing  rocks  in 
a  groove  running  across  the  lower  surface  of  the  top  carriage.  Both 
the  spring  cap  and  box  are  perforated  to  allow  the,  ends  of  the  spring 
rods  to  pass  freely  through  them. 

As  an  additional  precaution  against  shock  when  returning  to  the 
firing  position,  buffer  stops  are  provided.  These  are  made  up  of 
alternate  layers  of  balata  and  steel  plates,  and  are  held  between  the 
guides  under  the  caps.  The  crossheads  moving  between  the  guides 
during  counter  recoil  strike  these  buffers  when  the  mortar  returns  to 
the  firing  position,  and  are  maintained  in  pressure  contact  under  the 
guide  caps  by  the  counter-recoil  springs. 

ELEVATING  SYSTEM  (Plate  III). — A  circular  rack  of  cast  steel  is 
bolted  longitudinally  to  the  mortar  on  the  underside,  so  that  the 
center  from  which  its  pitch  line  is  struck  is  at  the  intersection  of  the 
axes  of  the  trunnions  and  bore.  This  rack  engages  in  a  pinion  of 
steel  mounted  on  a  heavy  s'naft  on  the  under  surface  of  the  top  car- 


14 

r 

riage,  which  also  carries  an  elevating  gear  to  which  motion  is  given 
this  gear  and  shaft  through  intermediate  gears  by  a  second  shaft 
extending  across  the  upper  face  of  the  top  carriage  and  bearing  a 
handwheel  at  each  end.  The  top  carriage  is  cored  out  to  permit 
the  passage  of  the  rack. 

The  mortar  is  held  hi  the  firing  positions  by  means  of  a  hand  nut 
on  the  handwheel  shaft,  which  locks  that  shaft  by  pressing  the  thrust 
collar  against  an  adjoining  bushing,  which  together  form  a  conical 
friction  clutch. 

To  protect  the  teeth  on  the  elevating  gearing  from  injury  which 
may  be  caused  by  inertia  effects  during  the  change  of  elevation  in 
recoil,  the  elevating  shaft  carries  a  friction  device.  This  device  con- 
sists of  alternate  bronze  and  cast-iron  disks  working  in  a  recess  of  the 
elevating  gear.  The  bronze  rings  rotate  with  the  elevating  gear  and 
the  cast-iron  rings  with  the  elevating  shaft  by  means  of  keys,  but  the 
keying  does  not  prevent  motion  in  the  direction  of  the  axis  of  the 
shaft.  By  means  of  a  nut,  plate,  and  coiled  spring  on  the  elevating 
shaft  the  rings  are  forced  together  and  against  the  elevating  gear, 
thus  forcing  the  latter  against  a  shoulder  of  a  bushing  which  is  rigidly 
fastened  to  the  elevating  shaft.  The  elevating  gear  is  not  fastened 
rigidly  to  the  shaft  or  to  the  bushing,  but  with  the  nut  and  spring  the 
pressure  between  them  can  be  made  great  enough  to  prevent  any 
slipping  during  elevating  or  depressing  or  an  undue  amount  of  slipping 
during  recoil.  This  pressure  will  be  properly  regulated  if  the  united 
effort  of  one  man  applied  at  each  of  the  handwheels  is  just  sufficient 
to  cause  a  slipping  when  an  attempt  is  made  to  depress  below  the 
minimum. 

More  accurate  adjustment  should  be  made  by  regulating  the 
friction  by  means  of  weights  or  a  spring  balance,  so  that  slipping 
will  occur  with  the  mortar  depressed  against  the  stop  when  a  force 
of  156  pounds  is  applied  to  the  elevation  handwheel  shaft,  at  a  dis- 
tance of  100  inches  from  the  center  of  the  shaft,  in  accordance  with 
General  Orders,  No.  63,  War  Department,  1914. 

To  hold  the  mortar  in  the  horizontal  position  for  loading  and  insure 
against  accidental  elevating  when  the  breech  is  open,  an  elevation 
lock  is  provided.  This  consists  of  a  lock  bar  and  spring  attached  to 
the  top  carriage  and  engages  a  lock  stud  on  the  elevation  rack,  thus 
automatically  locking  the  mortar  when  horizontal.  To  elevate  the 
mortar,  the  lever  which  serves  to  withdraw  the  lock  bolt  must  be 
operated  and  held  open  by  hand  until  the  mortar  has  moved  suffi- 
ciently in  elevation  for  the  stud  to  clear  the  lock  bar. 

On  each  side  of  the  elevating  rack  is  placed  an  auxiliary  eleva- 
tion scale  graduated  in  10-minute  intervals.  Pointers  attached  on 
each  side  of  the  opening  in  the  top  carriage  indicate  the  elevation  of 
the  mortar. 


15 

TRAVERSING  SYSTEM  (Plate  IV). — The  circular  traversing  rack  on 
the  inside  of  the  base  ring  has  meshing  with  it  a  pinion  on  a  vertical 
shaft  which  passes  down  through  the  racer  and  having  at  its  upper 
end  a  worm  wheel.  Motion  is  given  the  latter  by  means  of  a  hand- 
wheel  mounted  on  a  worm  shaft.  The  worm  shaft,  worm  wheel, 
and  the  part  of  the  vertical  shaft  above  the  racer  are  incased  in  a 
standard,  which  has  oil  and  drain  holes  so  arranged  that  the  worm 
and  the  gear  rim  run  in  oil. 

This  standard  is  of  cast  iron  for  model  of  1896  Mi  carriages,  and 
of  cast  steel  for  model  of  1896  Mil  carriages.  The  vertical  traversing 
shaft  is  of  cast  steel  for  model  of  1896  Mi  carriages  and  of  forged 
steel  for  model  of  1896  Mn  carriages. 

In  order  to  maintain  the  piece  without  further  movement  until 
fired  after  having  been  set  in  azimuth,  a  traversing  brake  is  applied. 
It  consists  of  a  toggle  and  coiled  spring  acting  to  cause  a  brake  shoe 
to  grip  the  traversing  rack.  The  brake  is  operated  from  the  top  side 
of  the  racer  near  the  azimuth  pointer  by  two  pedals — a  foot  lever 
and  a  catch.  Depressing  the  foot  lever  sufficiently  to  engage  the 
catch  raises  the  brake  shoe  from  the  brake  path  and  permits  free 
motion  of  the  racer.  Releasing  the  foot  lever  by  depressing  the 
catch  throws  the  brake  on. 

The  brake  should  be  so  adjusted  that  one  man  working  on  the 
handwheel  can  with  difficulty  just  traverse  the  carriage  when  the 
brake  is  on. 

AZIMUTH  CIRCLE  AND  POINTER. — A  brass  circular  strip  in  eight 
sections,  about  1  inch  wide  and  graduated  to  degrees,  is  attached 
to  the  top  side  of  the  azimuth-circle  castings  which  surround  the 
racer.  Attached  to  the  racer  is  a  small  brass  pointer  or  subscale. 
This  pointer  is  subdivided  to  0.05°  and  stamped  in  hundredths  of  a 
degree.  An  electric  light  is  attached  for  illuminating  the  scales,  and 
a  cast-iron  cover  when  closed  down  protects  the  subscale  and  the 
light. 

ELEVATION  QUADRANT. — To  save  time  in  bringing  the  mortar  to 
the  desired  elevation  and  to  avoid  inaccuracy  in  placing  the  quadrant 
and  holding  it  against  its  seat,  a  special  elevation  quadrant  has  been 
designed.  This  quadrant  is  similar  to  the  gunner's  quadrant,  but 
permanently  attached  to  the  left  rim  base  of  the  mortar,  and  con- 
sists of  a  bracket  with  a  toothed  arc  and  an  arm  hinged  at  the  other 
end.  The  arm  is  telescoped  and  its  front  bushing  carries  a  bubble, 
a  micrometer,  and  a  toothed  sector  which  is  constantly  pressed  out- 
ward by  a  spiral  spring.  The  teeth  of  the  sector  engage  in  the  teeth 
of  the  arc,  which  are  cut  in  degrees  from  45°  to  75°.  The  micrometer, 
which  gives  a  limited  movement  to  the  arm,  is  graduated  to  a  least 
reading  of  one  minute.  When  the  quadrant  is  set  to  the  required 


16 

angle  of  elevation  and  the  piece  loaded,  the  mortar  is  given  the  proper 
elevation  by  bringing  the  bubble  to  the  center  of  the  tube. 

A  canvas  cover  has  been  provided  which  should  be  kept  on  the 
quadrant  when  not  in  use. 

LANYARD  ATTACHMENT. — A  short  lanyard  is  attached  to  the 
underside  of  a  stopper  in  the  top  of  the  racer  in  rear  of  its  central 
opening  and  extends  below  a  pulley  on  the  pit  ladder,  thence  up- 
ward to  the  safety  lanyard  device,  and  thence  to  the  firing  mech- 
anism. The  safety  lanyard  device  consists  of  a  bridle  clip  fastened 
to  the  plug  set  in  the  face  of  the  breech,  and  a  ring  fastened  at  such 
a  distance  from  the  hook  end  of  the  short  lanyard  that  the  hook  of 
the  lanyard  and  ring  can  be  fastened  to  the  firing  mechanism  and 
the  bridle  clip.  While  loading  and  laying  the  mortar  the  ring 
should  be  on  the  clip.  A  pull  on  the  lanyard  is  resisted  wholly  by 
the  bridle  clip,  which  will  not  permit  the  ring  to  slip  off  and  allow 
a  pull  on  the  firing  mechanism  until  the  mortar  has  attained  an  ele- 
vation of  about  43°. 

The  long  lanyard  is  hooked  into  the  eye  on  the  top  of  the  stopper 
and  the  stopper  and  short  lanyard  drawn  to  the  rear  to  fire. 

ELECTRICAL  ATTACHMENTS. — These  consist  of  the  firing  circuit, 
its  safety  attachments,  and  the  lighting  circuits. 

FIRING  CIRCUIT. — The  current  for  the  firing  circuit  is  operated 
by  a  hand-operated  alternating-current  magneto,  type  MA,  located 
at  the  mortar  pit.  The  magneto  is  attached  to  a  bracket  (77A)  on 
the  wall  of  the  pit  and  connected  with  the  Engineer  plug  box  by  a 
flexible  cable  72  inches  long.  One  end  of  the  magneto  cable  is  con- 
nected to  the  terminals  (T97P  and  T97Q)  of  the  magneto  and  the 
other  end  is  connected  to  the  cable  plug  (P73D)  as  furnished  with 
plug  box  (E20B)  by  the  Engineer  Department.  The  magneto 
bracket  (77A)  is  furnished  by  the  Ordnance  Department  and  is  set 
up  on  foundation  bolts  installed  by  the  Engineer  Department.  The 
conduits  and  wiring  to  each  mortar  well  are  furnished  and  installed 
by  the  Engineer  Department  in  accordance  with  General  Orders, 
No.  1,  War  Department,  1913.  The  engineer  cable,  type  1,  termi- 
nates in  a  water-tight  receptacle  box  (E25H1)  bolted  to  the  under- 
side of  the  base  ring.  When  not  actually  in  use  this  box  is  kept 
closed  by  means  of  a  receptacle  cap  (E23J)  and  rendered  water- 
tight by  a  rubber  gasket. 

The  connection  between  the  fixed  base  ring  and  the  rotating  racer 
etc.,  is  accomplished  by  means  of  slicked  reinforced  cord,  No.  16 
(inclosed  twisted  pair,  each  approximately  2,583  circular  mils),  new 
code  Type  P.  W.  P.  To  facilitate  connecting  up,  the  inlet  end  of 
this  cord  terminates  in  a  plug  (E25Z)  which  can  be  quickly  inserted 
in  the  receptacle  referred  to  above,  the  joint  being  closed  by  means 


17 

of  a  plug  cap  (E23AC)  which  is  screwed  directly  to  the  receptacle 
cover,  and  rendered  water-tight  by  means  of  a  rubber  gasket.  From 
the  inlet-receptacle  box  on  the  base  ring  the  flexible  cord  is  led  verti- 
cally downward  to  the  bottom  of  the  well,  thence  beneath  two  hooks 
which  keep  it  always  below  the  spring  box  to  a  double  pulley  cen- 
trally located  on  a  three-legged  bracket  which  straddles  the  emplace- 
ment drain.  From  the  pulley  the  flexible  cord  is  led  to  the  left  side 
rib  of  the  racer  opening  where  it  terminates  in  a  receptacle  box 
(E25J1).  This  receptacle  box  is  similar  to  that  previously  men- 
tioned, but,  instead  of  a  screw  cover,  is  provided  with  a  spring  cover 
which  closes  automatically  whenever  the  safety  firing  plug  is  with- 
drawn, thereby  preventing  access  of  water  to  the  interior  of  the 
receptacle. 

The  plug  (E25Z1)  is  cut  away  on  one  side  so  that  it  can  be  inserted 
in  the  receptacle  box  (E25H1)  in  only  one  way.  This  is  necessary 
to  prevent  possible  short-circuiting  of  the  magneto  when  firing  more 
than  one  mortar. 

The  safety  firing  plug  (E25AA1)  is  similar  to  that  already  described, 
except  that  it  is  not  provided  with  a  cap  and  gasket  for  making  a 
water-tight  joint  when  inserted  in  the  receptacle.  This  is,  however, 
unneccessary  in  this  case,  as  the  plug  is  only  inserted  when  ready  to 
fire,  and  is  immediately  and  automatically  withdrawn  when  the  mor- 
tar is  depressed  after  firing.  From  this  plug  another  length  of  flexible 
cord,  looped  slack  in  order  to  let  the  plug  chain  take  the  strain,  leads 
to  the  face  of  the  breech,  where  one  lea'd  is  grounded  and  the  other 
fastened  directly  to  the  spring  plunger  of  the  circuit  breaker.  Eventu- 
ally it  is  intended  to  mount  a  small  transformer  on  the  face  of  the 
breech,  in  which  case  both  leads  will  be  brought  within  the  trans- 
former casing  through  water-tight  stuffing  tubes,  and  connected  to 
the  primary  coil  of  the  transformer.  The  purpose  of  this  transformer 
is  to  provide  a  break  in  the  metallic  circuit  between  the  magneto  and 
the  primer,  thereby  minimizing  to  a  great  extent  the  possibility  of 
premature  firing  due  to  accidental  grounds  or  crosses  between  the 
firing  and  lighting  circuits.  For  use  with  a  single-wire  primer  one  of 
the  secondary  leads  of  the  transformer  is  grounded  directly  to  the 
mortar  and  the  other  is  led  to  an  insulated  contact  piece  which  com- 
pletes the  circuit  with  the  corresponding  part  on  the  breechblock 
when  the  mortar  is  completely  rotated  to  its  locked  position. 

The  firing  plug  (E25AA1)  is  cut  away  on  one  side  to  insure  its 
being  inserted  in  the  receptacle  box  (E25J1)  in  one  way  only,  as 
explained  in  the  case  of  the  plug  (E25Z1). 

LIGHTING  CIRCUIT. — Current  for  the  lighting  circuit  is  supplied  by 
the  Engineer  Department  from  the  emplacement  mains,  and  is  led 
9977—17 3 


18 

into  each  well  by  Engineer  cable,  type  1,  terminating  in  a  water-tight 
receptacle  (E25AB),  as  previously  described  for  the  firing  circuit. 
The  connection  between  the  fixed  base  ring  and  rotating  racer,  etc., 
is  accomplished  in  a  manner  similar  to  that  for  the  firing  circuit, 
except  that  the  outlet  end  of  the  lighting  circuit  terminates  in  a  plug 
(E25AD)  similar  to  that  in  which  the  inlet  end  terminates.  In  con- 
necting up  the  lighting  circuits  this  plug  is  inserted  into  a  receptacle 
(E25AB)  which  is  permanently  screwed  into  a  junction  box  (E21T) 
located  at  the  left  side  of  the  racer  opening.  From  this  junction 
box  radiate  the  circuits  for  the  azimuth  lamp,  elevation  quadrant 
lamp,  and  portable  lamp.  These  circuits  are  made  up  of  twin- 
conductor,  lead-covered,  steel-armored  cable,  each  conductor  of 
4,110  circular  mils  cross  section,  both  ends  secured  to  their  respective 
terminal  points  in  a  water-tight  manner  by  the  use  of  stuffing  tubes 
(E21Z).  The  circuit  for  the  azimuth  lamp  passes  around  the  inside 
of  the  racer  opening  until  it  reaches  the  depression  for  the  azimuth 
pointer,  where  the  cable  is  connected  up  to  a  water-tight  receptacle 
box  (E22N)  which  supports  the  azimuth  lamp  and  reflector  (E12P2). 
The  circuit  for  the  quadrant  lamp  leads  to  the  upper  part  of  the  left 
crosshead  guide  where  the  cable  is  connected  to  a  quadrant  lamp 
bracket  (E22P),  which  supports  the  quadrant  lamp  and  reflector. 
The  circuit  for  the  portable  lamp  passes  to  the  rear  and  is  connected 
to  a  portable  lamp  plug  box  (E20B).  Plug  box  and  portable  lamp 
are  furnished  by  the  Engineer  Department. 

SAFETY  FEATURED. — In  order  to  prevent  possible  accidents  due  to 
the  crossing  of  the  firing  and  lighting  circuits,  the  plugs  (E25AD)  and 
(E25Z)  are  made  noninterchangeable,  in  that  the  firing  plug  can  not 
be  inserted  by  mistake  in  the  lighting  receptacle  on  the  base  ring. 
The  insertion  of  the  lighting  plug  in  the  firing  receptacle  would 
obviously  cause  no  damage,  but  in  order  to  prevent  mistakes  the 
words  "Firing"  and  "Lighting"  are  cast  in  raised  letters  on  the 
covers  of  the  corresponding  receptacles  wherever  used. 

In  order  to  prevent  accidents  due  to  firing  at  too  low  an  elevation, 
the  safety  firing  plug  is  suspended  from  the  breech  of  the  mortar  by  a 
chain  whose  length  is  determined  by  trial  as  only  sufficient  to  permit 
.contact  to  be  made  at  elevations  of  43°  and  above.  Automatic 
(closing  of  the  firing  circuit  at  this  point  is  omitted  advisedly. 

CARE  OF  ELECTRICAL  EQUIPMENT. — The  electrical  equipment  can 
be  divided  generally  into  two  distinct  classes — the  permanent,  rugged, 
and  expensive  installation  of  armored  cable  and  water-tight  accesso- 
ries on  the  base  ring  and  racer;  and  the  less  rugged  and  correspond- 
ingly inexpensive  but  easily  replaceable  flexible  cord,  which  should 
be  removed  from  the  carriage  and  stored  in  a  clean  and  dry  place  when 
not  actually  in  use.  In  the  second  class  are  included  the  complete 


19 

firing  circuit  and  that  part  of  the  lighting  circuit  between  the  inlet  on 
the  base  ring  and  the  junction  box  on  the  racer. 

Except  in  emergencies,  the  carriage  should  not  he  traversed  more 
than  180  degrees  to  the  right  or  left  of  a  line  perpendicular  to  the  flexible 
conductors  on  the  floor  of  the  mortar  well. 

SHOT  TRUCKS  AND  SHOT  TONGS. — The  shot  trucks  for  this  carriage 
are  constructed  so  as  to  admit  of  passing  the  shell  directly  from  the 
truck  into  the  mortar.  Each  truck  consists  of  a  light  rectangular 
framework  of  steel  mounted  on  four  rubber-tired  wheels  and  carrying 
a  pan,  in  which  the  shell  lies  horizontally  and  at  the  proper  height  for 
loading.  This  shell  pan  projects  to  the  front  and  is  designed  to  enter 
the  breech  of  the  mortar  and  to  supply  the  place  of  the  usual  loading 
tray.  Two  straight  wooden  bars  which  slip  into  sockets  on  each  side 
of  the  truck  serve  as  handles,  and  the  two  rear  wheels  are  swiveled 
to  facilitate  turning.  A  brake  is  attached  for  holding  the  truck 
firmly  in  position  against  the  breech  while  loading  or  unloading. 
Shot  tongs  are  also  provided  for  placing  the  shot  on  the  shot  truck. 
One  pair  of  tongs  is  provided  for  each  trolley  installed  by  the  Engineer 
Corps  and  two  pairs  are  kept  in  reserve  by  the  district  ordnance  officer 
for  each  battery. 

TOOLS  AND  ACCESSORIES  AND  IMPLEMENTS. — The  carriage  is 
equipped  with  the  tools  and  accessories  necessary  for  its  assembling 
and  care.  These  parts,  together  with  the  implements  for  the  mortar, 
except  those  too  large,  are  stored  in  an  armament  chest. 

ASSEMBLING    THE    CARRIAGE. 

IMPLEMENTS. — The  assembling  requires  machines  and  implements 
for  mechanical  maneuvers  usually  found  at  forts,  such  as  shears, 
falls,  blocking,  jacks,  sling  chains,  etc. 

GENERAL  REMARKS. — -The  size  of  the  carriage  is  such  that  it  must 
be  dismantled  for  shipment,  so  that  when  it  arrives  at  its  destination 
it  has  to  be  entirely  assembled. 

In  assembling  the  carriage,  as  in  all  machinery,  no  parts  should  be 
directly  struck  with  a  steel  hammer  or  sledge.  Soft-metal  drifts  or  copper 
or  lead  hammers  should  he  used. 

In  unloading  or  handling  the  parts  care  should  be  exercised  that  the 
edge  or  finished  surfaces  do  not  become  upset  or  burred.  When  two 
bearing  surfaces  are  brought  together  it  is  especially  necessary  that  both 
parts  should  be  absolutely  clean,  smooth,  and  well  lubricated. 

In  mounting  the  carriage  the  top,  bottom,  and  back  of  the  cross- 
head,  the  buffer  plates,  and  that  part  of  the  top  carriage  behind  the 
guides  will  be  painted  before  assembling.  These  parts  are  not  accessi- 
ble after  being  mounted,  and  if  not  thus  protected  would  rust  badly. 


of  the  order  in  which 

i 


to  its  position  over  the 
When  the  holes  in  die  ring 
by  means  off  jacks. 
If  it  should  be  nectar 
mck  by  means  off  the  lugs  on  the 
apart,  putting  a  piece  off  soft  wood 
Repeat  due  opentians  off  towering  until  the 
the  bolts  as  nearbr  central  in  the  holes  as 
off  every  platform  boh  there  should  be  an 

an  iron  plate  6  inches  long,  4 

proper  support,  faablmg  it  to  be  easily  leveled  by 
and  ako  permit  the  grouting  to  become  well 

parts  off  die 

level  and  an 


off  die  pfttdorm  bolts  and  nuts  should  be  canfuOy 
to  see  that  they  are  not  bmred  and  are  free  from  rust. 
After  tfcey  are  put  in  onler  thoroughly  oil  die  threads  off  both  boils 
In  sore-wing  down  the  nuts  on  die  platform  bolts  take 
at  a  time,  so  that  no  part  off  the 


and  ^stneNedse  ~  that  die  middle  of  die  level  is 

of  the  straightedge  with  the 
;  of  contact  on  the  straight^ 


always  be  reversed  and  the  mean  off 
the  true  reading.    The 
done  from  the  top  off  the  pintle,  if 
die  stra^itedfee  should   be 
off  die  roler  path,  following  around 
first  in  one  dhcrtion  and  then  in  die  other,  level- 
die  foundation  bolts  until  no  mgfr  spots  are 
property  fevefcd  and  fixed  in  die  place, 


poor  under  it  a  grafting  of  neat  Portland 
that  the  part  below  the  level  of  the 
embedded.     FIE  the  spaces  between  the 
melted  lead. 

DISTANCE  RDTCS  ASTD 
roller  path  and  roft 
emery  doth  and  then  assemble  the 
thk  is  done  ran  the 
that  they  ran  freely  and  do 
: .  :-i - 

vboh  the  «^*th  *zimtb-drdr  brackets  to  the  ftmgt  of  the 
base  ring,  care  being  taken  to  see  that  they 

_JM,    -  "B .M.^«  — .    a^ 

—  -:. .  --.-_      _.     ..-  ..i.  ..  -- 
RACES.— Before  aasembfimi  the  racer  the 


the  pintle 

with  keraeene  oil  and 

the  spring  box.  with  its  brackets  on  it.  inside  the 
the  position  it  wm  finally  oocupr.  with  the  top 
the  brackets  no  higher  than  the~floor  lerel  of  the 
means  of  skids  and  rollers  the 
place,  seeing  that  its 
floor  lerel  of  the 

qiring-box  brackets  and  spring  box.  by 
to  their  proper  position  against  the 
then  bolt  firmly  to  the  lAtei  by 
the  feet  of  the^  brackets,     tlf 
up.  the  spring  box 

mthji^ 

racer  is  placed  in  position  for  lowering.))     Lower  the 
roflers:  this  can  best  be  done  by  means  of  three 
apart,  care  being  taken  to  ktep'bfcekiBg  under  it  ami  to 
little  at  a  time.    When  in  place  ran  it  aiuaad  several  tancs  by 
to  see  that  it  runs  freely  and  the  pml  Ir  surfaces  do  not  biadL 


**d  dowel  and  bolt 
attached  to  the 
FUDOK  PLATE, 


,4>ead 

ladder  to  the  inner  surface  of  the  fUn^r  on  the  frimt  of  thr 
and  its  brace  to  the  under  surface  of  the  floor  plate  m  the  rear.    After 
this  the  dust  guards,  in  four  sectinoss  can  be  bofted  o»  the 
interior  flange  of  the  racer  just  in  idt  the  •  naV  •  path 


22 

RECOIL  CYLINDERS. — To  prepare  the  cylinders  for  assembling, 
remove  the  guides  and  caps  and  then  the  crossheads,  take  out  the 
top  cylinder  heads,  remove  the  piston  rods,  and  clean  the  cylinders 
thoroughly.  Then  coat  the  upper  interior  parts  of  the  recoil  cyl- 
inders and  that  part  of  the  piston  rods  below  the  piston  head,  which 
will  be  above  the  level  of  the  oil,  with  light  slushing  oil,  to  prevent 
the  formation  of  rust  in  the  space  above  the  level  of  the  oil  in  the 
cylinders.  After  oiling  the  parts,  replace  the  piston  rods  and  cyl- 
inder heads. 

Removal  of  the  piston  rods  will  necessitate  reassembling  and  repacking 
the  stuffing  boxes.  See  "Care  of  the  carriage." 

Now  clean  the  trunnions  of  the  cylinders  and  then  lower  the  cylin- 
ders into  their  respective  openings  in  the  racer  and  side  frames  and 
bolt  on  the  cap  squares. 

TOP  CARRIAGE. — With  the  aid  of  rollers  run  the  top  carriage  bot- 
tom side  up  to  the  front  of  the  racer  and  set  in  the  fulcrum  pins  and 
their  keys  and  set  screws.  Using  shears,  gin,  or  jacks,  raise  the 
trunnion-bed  end  of  the  top  carriage  up  past  the  vertical  unit  until  it 
inclines  well  to  the  rear,  when  it  should  be  braced  preparatory  to 
receiving  the  mortar.  The  cap  squares  should  now  be  removed. 

COUNTER-RECOIL  SPRINGS. — To  assemble  the  springs  the  center  of 
the  mortar  trunnions  should  be  about  5  feet  9  inches  above  the  racer. 
Put  five  springs  in  the  spring  box  and  lower  through  them  the  spring 
rods  with  the  locking  and  adjusting  nuts  down  against  the  fixed  nuts. 
Now  assemble  the  springs  and  washers  on  the  rods,  four  on  each  rod 
above  washers,  and  with  the  aid  of  a  tackle  let  fall  to  their  approxi- 
mate position  against  a  scantling  which  had  previously  been  located. 
The  spring  cap  should  then  be  placed  in  position. 

To  MOUNT  THE  MORTAR  BY  BLOCKING  the  following  articles  are 
required:  Oak  rollers  3  feet  long;  one  cradle  18  feet  long  and  3  feet 
wide;  two  12-inch  timbers  26  feet  long,  and  two  of  the  same  length 
as  the  crib  work;  a  quantity  of  2-inch,  6-inch,  8-inch,  and  12-inch 
blocking,  and  three  hydraulic  jacks  of  15-ton  capacity.  On  the 
emplacement  floor  in  front  and  rear  of  the  racer  make  two  parallel 
crib  works  of  blocking  longer  than  the  width  of  the  top  carriage. 
They  should  be  sufficiently  high  to  allow  the  two  long  12-inch  timbers, 
now  laid  from  one  crib  to  the  other,  to  clear  the  top  carriage.  The 
outer  faces  of  these  pieces  should  be  within  the  planes  of  the  inner 
faces  of  the  trunnion  beds: 

Build  a  runway  in  front  of  the  carriage,  so  that  the  mortar  on  the 
cradle  can  be  removed  on  the  track  just  formed,  and  bring  the  trun- 
nions of  the  piece  over  their  beds.  Carefully  chock  the  rollers. 

To  REMOVE  CRADLE  AND  TRACK. — Insert  a  heavy  block  in  breech 
of  mortar,  allowing  it  to  project  1  foot  outside.  Place  head  of 
hydraulic  jack  under  this  block  close  to  breech  and  its  foot  on  the 


23 

cradle  and  raise  sufficiently  to  pass  a  12-inch  timber  between  mortar 
and  cradle  at  right  angles  to  mortar,  and  block  up  each  end  on  crib- 
work  outside  of  cradle.  The  crosspiece  must  now  clear  the  cradle. 
Repeat  the  operation  at  muzzle  and  chock  the  piece  front  and  rear. 
Remove  cradle,  rollers,  and  track. 

To  LOWER  THE  PIECE. — Jack  up  the  breech  as  above  described, 
remove  sufficient  of  the  crib  to  allow  a  4-inch  drop,  and  lower  the 
breech  onto  the  cross  timbers.  Do  same  at  muzzle,  and  continue 
until  trunnions  are  in  their  beds.  Then  bolt  on  the  cap  squares. 

The  clearance  between  crosshead  guides  and  end  of  trunnion  is 
small,  so  great  care  must  be  taken  in  lowering. 

Remove  the  braces  supporting  the  top  carriage  and  lower  the  mor- 
tar and  top  carriage  against  the  springs,  the  top  carriage  rotating 
about  the  fulcrum.  It  will  be  necessary  to  guide,  with  a  crowbar,  the 
spring  rods  through  the  openings  in  the  spring  cap  and  top  carriage. 
If  the  weight  of  the  mortar  and  top  carriage  is  insufficient  to  compress 
the  springs  enough  to  enter  the  piston  rod  nuts  in  the  crosshead,  the 
latter  having  previously  been  bolted  to  the  crank  pins,  a  tackle 
should  be  used  to  draw  the  mortar  down. 

To  CONNECT  THE  PIECE  WITH  THE  RECOIL  SYSTEM. — Screw  the 
piston  rod  nuts  with  great  force  into  the  crossheads,  assemble  the 
guides  to  the  cylinders,  embracing  the  crossheads,  and  bolt  on  the 
guide  caps  with  their  balata  buffers.  See  that  the  guides  and  cross- 
heads  are  well  cleaned  and  oiled  before  they  are  put  in  place.  Connect 
the  equalizing  pipe  with  the  recoil  cylinders. 

ELEVATING  GEAR. — Slip  the  elevating  rack  through  the  hole, 
intended  for  it  in  the  top  carriage  and  bolt  it  securely  to  the  mortar. 

Slide  elevating  shaft  through  its  bearings,  friction  device,  and  ele- 
vating pinion,  screwing  up  on  the  clutch  spring,  adjusting  nut  at  the 
same  time.  Bolt  elevating  nut  pin  bracket  to  the  underside  of  the 
top  carriage.  Slide  elevating  intermediate  pin  through  its  bearings 
and  elevating  intermediate  gears  and  fasten  with  tap  bolt.  Place  in 
position  the  idler  pin  and  elevating  idler  gear  fastening  with  tap  bolt. 
Bolt  in  place  the  elevating  handwheel  shaft  brackets  and  assemble  in 
position  handwheel  shaft  with  handwheels  and  collars. 

ADJUSTMENT  OF  SPRINGS. — After  the  mortar  is  in  position  it  may 
be  found  that  the  springs  have  not  been  compressed  sufficiently  to 
hold  the  mortar  in  the  firing  position,  and  that  there  are  open  spaces 
between  the  crossheads  and  the  caps  on  the  crosshead  guides.  These 
spaces  must  be  closed  by  an  additional  compression  of  springs.  For 
this  purpose  the  lock  nuts  on  the  five  spring  guide  rods  are  loosened 
and  the  necessary  compression  given  by  the  adjusting  nuts,  the 
spindles  being  held  from  turning  by  means  of  the  fixed  nuts  immedi- 
ately over  the  loose  springs.  During  the  adjustment  of  the  springs 


24 

the  mortar  should  be  occasionally  jarred  against  the  stop  on  the  top 
carriage  by  means  of  the  elevating  handwheels.  The  elevation  lock 
must  be  held  unlocked  when  the  mortar  is  jarred  against  the  stop  in 
order  to  prevent  the  breaking  of  the  lock  when  the  mortar  rebounds 
from  the  stop.  The  proper  compression  is  given  when  the  springs 
will  hold  the  crossheads  in  pressure  contact  under  the  guide  caps. 

TRAVERSING  MECHANISM. — Thoroughly  clean  all  the  traversing 
mechanism  preparatory  to  assembling,  first  detaching  the  parts  which 
have  been  shipped  assembled.  Then  put  the  worm  and  worm  wheel 
in  the  pedestal  brackets,  engage  the  gears,  and  insert  the  worm  shaft. 
Next  put  the  vertical  traversing  shaft  through  the  pedestal  bracket 
from  the  lower  end.  Key  the  upper  end  of  the  shaft  to  the  worm 
wheel,  put  on  the  washer  and  nut,  and  insert  the  split  pin.  Bolt  the 
bracket  for  vertical  traversing  shaft  to  its  pad  on  the  underside  of  the 
racer.  Support  the  traversing  pinion  in  its  place,  engaging  the  rack, 
shrouded  side  up.  Lower  the  assembled  pedestal  bracket,  allowing 
the  vertical  shaft  to  enter  its  lower  bearing  and  pinion.  Bolt  the 
pedestal  bracket  to  its  pad  on  the  racer  and  attach  the  traversing 
handwheel.  If  necessary,  turn  the  handwheel  to  adjust  the  keyway 
for  the  traversing  pinion  and  secure  the  pinion  with  key,  washer,  and 
nut.  Put  on  the  cover.  Attach  traversing  brake. 

AZIMUTH  CIRCLE. — The  azimuth-circle  castings  should  next  be  put 
in  place,  fitting  the  ends  together  as  marked,  care  being  taken  to  see 
that  the  inner  edge  of  the  circle  is  central  with  the  racer  and  83.5 
inches  radius,  so  that  the  clearance  between  it  and  the  racer  is  the 
same  all  around.  Then  bolt  on  the  angle-iron  brackets  to  support 
the  floor  plates  and  level  them  up  with  the  plates  on  them,  the  outer 
ends  being  blocked  up.  The  outer  point  at  which  these  angle  brack- 
ets are  supported  temporarily  must  not  be  more  than  22  inches  from 
the  racer  or  else  the  supports  will  interfere  with  the  filling  in  of  the 
emplacement  with  concrete,  which  is  to  form  the  sides  of  the  mortar 
pit  and  hold  the  brackets  rigid. 

IMPORTANT  POINTS. — After  the  carriage  has  been  completely  as- 
sembled and  the  mortar  mounted,  the  following  points  should  be 
noted,  viz: 

1.  Traverse  the  carriage  each  way  and  elevate  and  depress  the 
mortar,  to  see  that  they  work  freely. 

2.  Examine  and  clean  out  all  oil  holes,  noting  that  they  have  oil 
plugs. 

3.  See  that  there  is  not  a  hard  bearing  between  the  rim  bases  of 
the  mortar  and  the  top  carriage,  between  the  crossheads  and  crank- 
pin  shoulders,  and  between  the  cylinder  rim  bases  and  their  bearings, 
as  these  conditions  would  indicate  parts  out  of  alignment. 

4.  See  that  the  elevating  rack  is  firmly  attached,  that  the  coun- 
ter-recoil springs  maintain  the  mortar  fully  ain  battery/7  and  that 


25 

the  elevation  stop  permits  the  piece  to  be  depressed  to  horizontal 
position  so  that  projectiles  can  be  rammed  without  interference.. 

5.  See  that  the  dust  guard  does  not  bind  or  rub  on  the  traversing 
rack  and  that   the  inner  edge  of  the   azimuth-circle  castings   are 
concentric  with  the  revolving  racer. 

6.  Attach  the  elevation  quadrant,  using  a  clinometer  supported  by 
a  rest  in  the  muzzle  of  the  piece  while  fitting  it,  to  test  its  adjust- 
ment.    With  the  piece  set  horizontal  the  leveling  of  the  base  ring 
can  be  tested  by  traversing  to  each  90°  position  and  noting  the  reading 
of  the  clinometer. 

7.  Orient  the  mortar,  add  numbers  to  the  degree  marks  on  the 
azimuth  circle,  and  adjust  azimuth  pointer  to  indicate  correct  azimuth. 
Muzzle  at  true  south  is  0°  in  azimuth  and  numbers  are  placed  around 
clockwise  to  include  359. 

8.  See  that  electrical  connections  have  been  properly  made  by 
trying  the  lights  and  the  firing  circuits. 

To  DISMOUNT  CARRIAGE  FOR  PURPOSE  or  CLEANING  TRUNNIONS 
AND  SPRINGS. — Remove  crosshead  guides  and  guide  caps  and  unscrew 
piston-rod  nuts.  Then  with  the  aid  of  jacks,  skids,  and  blocking 
raise  the  mortar,  the  carriage  rotating  about  the  fulcrum  until  the 
center  of  the  trunnions  is  about  5  feet  9  inches  above  the  racer.  The 
spring  cap,  spring  washers,  and  rods  can  then  be  removed.  With 
the  springs  out  the  trunnion  cap  squares  can  be  removed  and  the  top 
carriage  lowered  sufficiently  to  clean  the  trunnions  and  their  beds. 
The  same  operation  in  the  reverse  order  should  be  followed  when 
assembling. 

CARE    OF   THE    CARRIAGE GENERAL    INSTRUCTIONS. 

Carriages  should  be  traversed  from  time  to  time  through  their 
entire  movement,  and  left  at  a  different  azimuth  each  time. 

It  is  especially  required  that  all  parts  of  the  carriages  must  be  kept 
free  from  rust  at  all  times.  If  this  be  allowed  to  accumulate  its 
removal  from  all  bearing  parts,  and  especially  piston  rods,  requires 
particular  attention  in  order  that  clearances  shall  not  be  unduly 
increased.  The  use  of  sandpaper  for  this  purpose  is  forbidden,  and 
emery  cloth  No.  1,  being  coarse  enough  for  any  ordinary  rusting, 
should  be  used,  the  rust  being  softened,  if  necessary,  by  coal  oil. 

If  any  leakage  occurs  from  the  hydraulic  recoil  system,  it  should 
be  immediately  remedied,  calling,  if  necessary,  upon  the  district 
armament  officer  for  the  services  of  skilled  labor. 

The  repacking  of  stuffing  boxes  may  be  done  when  necessary  by 
trained  enlisted  men  under  the  supervision  of  an  officer,  but  will 
preferably  be  done  by  skilled  labor. 


26 

Before  removing  a  cylinder  head  containing  a  stuffing  box,  or  draw- 
ing a  piston  rod  through  a  stuffing  box,  the  pressure  of  the  packing  on 
the  rod  should  be  released  by  unscrewing  the  follower  several  turns. 

The  vulcanized  fiber  or  copper  gaskets  between  cylinders  and  their 
heads  should  be  in  good  condition  and  consequently  should  be  replaced 
whenever  necessary  in  order  to  prevent  leakage. 

Recoil  cylinders  should  be  emptied  at  least  every  three  months  and 
thoroughly  cleaned  every  six  months. 

CLEANING  RECOIL  CYLINDERS. — For  this  cleaning  a  plumber's  hand 
force  pump  will  be  supplied  to  each  Coast  Artillery  post,  with  about 
10  feet  of  suction  hose  and  15  feet  of  discharge  tube. 

It  will  be  noted  that  in  no  case  will  it  be  necessary  to  remove  the 
packing  from  the  stuffing  box  -to  clean  the  cylinders. 

In  cleaning,  the  following  order  of  operations  may  be  followed : 

(a)  Remove  oil  from  cylinders  and  equalizing  pipes. 

(6)  Compress  the  counter-recoil  springs  by  means  of  the  assembling 
screws,  so  as  to  lower  the  mortar  a  few  inches,  remove  the  guides  and 
caps  and  disconnect  and  remove  the  crossheads. 

(c)  Unscrew  the  cylinder  heads  and  carefully  withdraw  the  piston 
rods  out  of  the  cylinders.     Each  part  dismounted  should  be  marked 
to  insure  its  being  assembled  in  its  correct  place. 

(d)  Thoroughly   clean   the   cylinders   with   coal   oil   forced   from 
a  hand  pump  into  both  ends  of  each  cylinder.     The  plug  in  the 
emptying  coupling  should  be  removed  and  both  branches  of  the 
equalizing  pipe  flushed  out  from  their  cylinder  ends.     Then  wipe 
the  interior  of  the  cylinders  dry  with  clean  cotton  waste  and  clean 
the  piston  rods  and  cylinder  heads. 

0)  Replace  the  emptying  coupling  plug,  assemble  the  piston  rods, 
cylinder  heads,  crossheads,  caps,  and  guides,  exercising  great  care 
that  none  of  the  parts  are  burred  or  otherwise  damaged.  The  cylin- 
der heads  should  be  firmly  screwed  into  place,  care  being  taken  that 
the  packing  ring  is  in  good  condition  and  properly  placed.  Screw 
the  followers  tight  against  the  packing  in  the  stuffing  boxes. 

(/)  All  parts  dismounted  should  be  carefully  inspected  to  ascertain 
that  they  have  been  properly  assembled. 

REMOVING  PACKING  FROM  STUFFING  BOXES  (using  new  extractor 
furnished  by  the  Ordnance  Department). — Close  the  extractor  around 
the  piston  rod  and  insert  the  locking  pin.  Turn  the  extractor  to 
the  left,  with  pressure  on  the  packing,  until  the  needles  are  firmly 
engaged  in  the  packing.  Draw  the  packing  out,  turning  slowly  to 
the  left.  In  the  case  of  a  box  with  interior  thread  and  if  the  ring 
is  tight  it  should  be  unscrewed  and  not  stripped  out  by  the  thread, 
because  unless  unscrewed  it  would  catch  upon  and  be  injured  by  the 
thread. 


27 

Extractor  bars  are  provided  to  be  used  for  starting  the  packing 
from  its  seat  and  by  inserting  the  toes  of  the  bars  in  the  rack  teeth 
and  prying  over  the  edge  of  the  box,  being  careful  not  to  injure  the 
thread. 

To  PACK  A  STUFFING  Box. — To  pack  a  stuffing  box,  after  drawing 
the  oil  from  the  cylinders,  remove  the  follower  and  with  it  the  rings 
and  all  the  packing  in  the  box.  Examine  the  old  packing  and  dis- 
card all  unfit  for  use.  If  any  of  the  old  packing  is  used,  it  should  be 
put  in  after  the  new. 

In  packing  a  stuffing  box  put  on  the  piston  rod  one  ring  of  0.625- 
inch  Oarlock's  " waterproof  hydraulic"  packing,  and  force  it  well  to 
the  bottom  of  the  stuffing  box  by  a  wooden  stick  and  mallet.  Treat 
each  layer  of  packing  in  a  similar  manner,  until  the  required  amount, 
with  the  old  on  top  when  any  of  the  latter  is  used,  is  inserted. 

Put  the  halves  of  the  ring  on  the  follower,  enter  them  together  in 
the  box,  and  screw  up  the  follower,  being  careful  to  note  that  the 
halves  of  the  ring  do  not  bind  on  the  screw  threads. 

No  more  force  should  be  used  on  the  spanner  wrench  than  that  of  two 
men,  and  generally  that  of  one  man  is  sufficient.  The  addition  of  a  pipe 
to  the  end  of  the  spanner  wrench  should  not  be  permitted. 

When  the  box  is  properly  filled  and  the  follower  tightened  there 
should  be  for  the  lower  boxes  not  more  than  1  inch  of  space  between 
the  flange  of  the  follower  and  the  piece  into  which  the  follower  is 
screwed.  For  the  upper  boxes  there  should  be  not  less  than  24  inches 
between  the  followers  and  the  piston-rod  nuts. 

The  follower  should  be  tightened  from  time  to  time.  If  the  fol- 
lower is  screwed  into  the  stuffing  box  too  tightly,  an  unnecessary 
amount  of  friction  will  be  produced  on  the  piston  rod.  When  the 
follower  is  screwed  in  until  the  flange  strikes  the  box  another  ring  of 
packing  should  be  inserted. 

It  is  to  be  expected  that  a  slight  amount  of  oil  will  soak  through 
and  drip  from  boxes  or  carriages  when  not  in  use.  Also,  when  tight- 
ening the  followers,  a  slight  amount  of  oil  will  squeeze  out  of  the  sat- 
urated packing.  This  oil  should  be  caught  and  not  allowed  to  render 
the  carriage  unsightly. 

FILLING  RECOIL  CYLINDERS. — To  fill  the  cylinders  with  oil,  remove 
the  two  plugs,  one  in  each  cylinder.  Pour  clean  neutral  oil  of  specific 
gravity  about  0.85  (such  as  the  "hydroline"  now  issued  to  the  service) 
into  the  hole  of  one  cylinder  until  it  flows  out  of  the  hole  of  the  other. 
Allow  any  air  that  may  be  present  to  escape,  then  pour  in  more  oil 
until  the  same  is  level  with  the  filling  holes.  About  9.5  gallons  are 
required. 

SERVICE  CONDITION  (LUBRICATION,  ETC.). — When  the  carriage  is 
to  be  kept  in  readiness  for  service  and  is  in  daily  or  frequent  use  all 
bearing  parts  must  be  kept  clean  and  lubricated.  Special  attention 


28 

should  be  given  to  the  lubrication  of  trunnion  bearings,  crossheads 
and  guides,  rollers,  pintle  surfaces,  elevating  rack  and  gears,  and 
traversing  mechanism,  including  the  teeth  of  all  gears. 

The  above  parts  should  be  lubricated  at  frequent  intervals  whether  the 
carriage  is  maneuvered  or  not.  When  carriages  are  in  use  for  daily 
drills  a  thorough  lubrication  twice  each  week  should  be  sufficient  for  all 
but  the  most  severely  used  parts. 

Proper  lubricating  and  cleaning  of  the  traversing  rollers  and  their 
paths  are  essential  to  the  free  working  of  the  carriage. 

When  oiling  the  rollers  or  the  pintle  the  carriage  must  be  traversed  in 
order  to  distribute  the  oil  throughout  the  whole  circumference. 

It  will  occasionally  be  necessary  to  examine  the  rollers,  to  see  that 
the  dust  guards  are  in  proper  place  and  that  the  rollers  themselves 
are  clean.  If  they  are  found  dirty  they  must  be  cleaned  with  kero- 
sene oil,  but  care  must  be  taken  to  fill  the  bearings  with  synovial  oil 
after  the  kerosene  has  been  rubbed  dry.  Experience  has  shown  that 
recoil  cylinders  should  not  remain  empty,  as  in  that  case  the  interior 
walls  soon  become  rusty. 

OIL  HOLES. — Oil  holes,  where  provided,  must  be  cleaned  out  fre- 
quently to  keep  them  free  from  sand  and  grit  and  will  habitually  be 
kept  closed  by  the  screw  plugs  provided,  except  when  in  the  act  of 
oiling. 

Before  oiling  at  any  hole,  wipe  off  carefully  any  dirt  or  grit  near  the 
opening  that  might  be  carried  down  into  the  bearing  by  the  oil. 

COMPRESSION  GREASE  CUPS. — Where  compression  grease  cups  are 
provided  similar  precautions  against  dirt  or  grit  must  be  observed. 
In  filling  these  cups  do  not  fill  the  cup  completely,  but  fill  only  to  the 
bottom  of  the  bevel  at  the  top  of  the  cup;  if  too  full,  the  leather 
packing  will  become  inverted  and  will  not  act  effectively.  In  putting 
on  the  cap  see  that  the  leather-packed  follower  enters  the  cup  with- 
out being  caught,  cut,  or  bent  by  the  edge  of  the  cup,  or  otherwise. 
Screw  the  cap  down  on  the  cup,  using  a  wrench,  if  necessary,  to 
secure  sufficient  power,  until  the  spring  rod  projects  about  0.25  inch 
above  the  top  of  the  cap.  Later,  when  the  spring  has  recovered  and 
has  moved  the  follower  forward,  forcing  the  grease  through  the  tube 
into  the  bearings,-  which  will  be  indicated  by  the  spring  rod  being 
pulled  into  the  cap  until  its  nut  touches  or  nearly  touches  the  cap,  it 
will  again  be  necessary  to  screw  up  the  cap  on  the  cup  until  the  spring 
is  again  compressed.  When  the  cap  is  screwed  nearly  home  and  the 
spring  rod  does  not  project  it  is  an  indication  that  the  cup  should  be 
refilled. 

For  further  information  regarding  paints,  oils,  cleaning  material, 
and  methods  of  using  same  see  Ordnance  Department  pamphlet 
Form  No.  1869.  Annual  allowances  will  also  be  found  therein. 

See  also  Circular  No.  29,  War  Department,  1910. 


Names 


of  parts  of  12-inch  mortar  carriages,  model  of  1896  Mi  and  model  of  1896  Mn, 
their  piece  marks,  location,  and  material  of  v:hich  they  are  made. 


The  parts  are  listed  alphabetically  under  the  following  headings  Carriage  proper;  the  electrical  equip- 
ment, including  the  firing  circuits,  ammunition  truck;  shot  tongs;  lanyard  attachment;  elevation  quadrant; 
and  grease  cup. 

When  referring  to  a  part,  always  mention  its  piece  mark,  where  given  on  the  list. 


Br Brass. 

Bz Bronze. 

C Copper. 

C.  I Cast  iron. 

C.  R.  S Cold  rolled  steel. 

Cond Condensite  or  equal. 

C.  S Cast  steel. 

F.V.F Flexible  vulcanized  fiber. 

G.  I Galvanized  iron. 

G.  S German  silver. 

G .  AY .  H .  P Garlock  waterproof  hydraulic 

packing. 
H.  R Hard  rubber. 


L Lead. 

M.I Malleable  iron. 

P.  Bz Phosphor  bronze. 

S Steel. 

S.  B «, Sheet  brass. 

S.  C Sheet  copper. 

S .  R Sheet  rubber. 

S.  S Sheet  steel. 

Sp.  S Spring  steel. 

V.  A vulcanized  asbestos. 

V.  F Vulcanized  fiber. 

W.  I Wrought  iron. 


12-INCH   MORTAR   CARRIAGE,  MODEL   OF   1896  Ml. 


Piece 
mark. 

No. 

Name  of  part. 

Location. 

Material. 

Remarks. 

U45M 
U45N 
U45AA 

N18B 

11E 
11J 
13EA 

N20G 
11C 

1 
1 

8 
8 
1 
1 
8 
1 
1 
1 
1 
1 
15 

3 
1 
1 
1 
12 
16 

16 
36 

8 
28 
4 
2 
2 
4 
4 

4 

1 

1 
5 
2 
2 
2 
8 
8 
4 
4 
2 
8 
8 
8 
36 
1 
2 
1 

4 

4 

8 
8 
1 

Adjusting  plug 

In  upper  brake  lever 

S 

Complete. 
In  8  sections. 

0.75  by  3.5. 

0.75  by  2. 
0.75  by  1.75. 
0.5  by  2. 
0.75  by  3. 
0.75  by  3. 
1.25  by  3. 

0.75  by  2.25. 
0.5  by  1. 
2  by  4.25. 
1.5  by  4.5. 
0.75  by  1.5. 
0.75  bv  1.5. 
1  by  f.75. 
1.375  by  2.625. 
0.75  by  2.25. 

0.75  by  2.25. 
0.75  by  1.5. 

0.75  by  1.5. 
0.875  by  2.25.  ' 
0.625  by  1.125. 
0.5  diameter. 
2  by  11.5. 
Iby3. 
0.375  bv  1.25. 
0.625  by  2.25. 
1.25  by  3.75. 
0.375  by  1.75. 
1.25  by  4.5. 
1.25  by  4.75. 
1  by  2.75. 
1  by  3.6. 

0.75  by  2. 
0.625  by  5. 

1  by  5.25. 

1  by  4.5. 
1.5  by  5. 
1.25  by  6.25. 

In  adjusting  plug 

s 

Angle  irons 

Under  floor  plate       

s 

do 

do 

s 

Armament  chest 

With  4  carriages   

Oak. 

Azimuth  circle  

On  azimuth  circle  bracket.. 
On  base  ring  

On  racer                . 

0.1... 

c.s  

S  B 

Azimuth  circle  bracket.. 

Base  ring 

On  platform  
In  armament  chest  

C.  I.  No.  2.  . 

s 

Bar  screw  driver 

do 

do  

S.... 

do 

do    

s 

Bolt,  countersunk,  with 
nuts, 
do 

Floor  plate  to  anale  . 

Bz 

For  pit  ladder  

s 

do 

For  pit  ladder  brace  

s  

..      do       

For  quadrant  bracket  
Floor  plate  to  angle  
For  traversing  rack  

Bz  
Bz  

s 

Bolt  (special) 

Bolt  tap 

do 

Azimuth  circle  bracket  to 
base  ring. 
Azimuth  circle  to  bracket.. 

s  

do 

s 

do 

s 

Bolt  tap  (special) 

For  cap  squares  

s 

B  olt  tap 

Side  frames  to  racer 

s 

do 

For  equalizing  pipe  bracket. 
For  elevating  shaft  bushing  . 
For  lower  brake  lever  stop.  . 

s  . 

do           

s... 

do 

s  

do              

For  elevating  rack  

s  

do                    .... 

Hand  wheel  shaft  bracket, 
right. 
Handwheel  shaft  bracket, 
left. 
For  elevating  intermediate 
pin  bracket. 
For  idler  pin     

s  

do                 

s  

do 

s  . 

do 

s.. 

do                 

For  elevating-lock  bracket.  . 

s  

do 

For  elevating-lock  strap.. 

s  

For  drip  pan 

s 

Bolt'  tap 

For  spring-box  bracket 

s 

do 

s  

do 

Cover  to  pedestal 

s 

do 

For  foot-lever  bracket  

s  

do 

Bracxet  to  racer 

s  . 

do 

For  left-hand  scale  

Q  

Bolt  with  nuts 

Azimuth  circle  sections.. 

s.        .  . 

do    -  

...do.... 

s  

do                        ... 

do  

s  

do 

Fnr  distnnpp  riny 

s. 

do                                            '    For  plp.vatinn  lnr»k- 

s 

do 

For  equalising  pipe  bracket. 
For  clutch-spring  adjusting 
nut. 
For  elevating  intermediate 
pin  bracket. 
..  ..do  

s  

do 

s 

do 

s.  . 

do 

s... 

do 

Cylinders  to  guides  
Caps  (13F)  to  guides  

s  
s  

....do  

Box.. 

r  or  sorines  

C.I.  No.  2.. 

30 

NaTnes  of  parts  of  12-inch  mortar  carriages,  model  of  1896  Mi  and  model  of  1896  Mil , 
their  piece  marks,  location,  and  material  of  which  they  are  made — Continued. 

12-INCH  MORTAR  CARRIAGE,  MODEL  OF  1896  Mi— Continued. 


Piece 
mark. 

No 

1 

1 
1 
1 
1 
1 
2 
1 
1 
1 

2 

48 
4 
1 

1 
3 
1 

1 
1 

1 

2 
5 

2 
1 
2 

1 

4 
2 
1 
1 
1 
1 
1 
1 

1 

4 
2 
1 

1 

1 

2 
1 
25 

25 

4 
1 
1 
1 
1 
1 
1 
2 
10 
2 
1 
2 
2 
1 
1 
1 
1 
1 
1 
1 

Name  of  part. 

Location. 

Material. 

Remarks. 

U44AB 

N18D 
N18E 
11D 

13K 
13F 

13S 
13CA 

IIP 

5A 

6A 
13G1 
13H1 
13Y2 
13Z2 
13X1 
13V 
13W 

U43L 
U43J 
TJ43AK 
U43AN 
U43F 
U43C 

Box  wrench  

In  armament  chest 

F  S 

For  elevation  lock. 
For  vertical  shaft. 

2  right,  2  left. 
For  elevating 
handwheel  shaft. 
Do. 
For  elevating  shaft 

For  vertical  shaft. 
For    handwheel 
shaft. 

2  right,  2  left. 
1  right,  1  left. 

For  Mr  carriage. 
For  Mil  carriage. 

No.  9,  olive  drab. 

1  right,  1  left. 

In  6  sections. 
2  and  2.5. 
1.5  and  1.75. 
1.25  and  1.375. 
1  and  1.125. 
0.625  and  0.75. 
0.375  and  0.5. 

Bracket. 

C.  S.  No.  2. 
C  I 

do  

Under  racer 

...do... 

C  S 

do 

For  elevation  quadrant  
do  

Bz  

C  S 

Bracket  base  

Brake  lever  pins  

In  bracket 

s 

Brake  link  

Through  racer 

s 

Brake  link  spring  

On  brake  link.  .          .  .  .  . 

s 

Brake  link  lower  pin  
Brake  link  upper  pin  

In  brake  link  

s.... 

do  

s 

Brake  shoes. 

C.S.No.l... 
Bz  
Bz 

Bushings  

On  traversing  rollers  
In  side  frames.        

Bushing  (in  halves)  ...... 
Bushings  

In  top  carriage 

Bz 

do 

do 

Bz 

do  

do 

Bz 

Bushings  (long)  

In  elevating  intermediate 
gears. 
...    do  

Bz 

Bushings  (short)  

Bz 

Bushings 

In    elevating    handwheel 
shaft  bracket  (right). 
In    elevating    handwheel 
shaft  bracket  (left). 
In  crossheads  (13G1)  (13H1) 
In  washers,  or  spring  guide 
rod. 
In  spring  box  brackets  
In  pedestal  bracket  
do           

Bz 

....  do 

Bz 

do 

Special  Bz... 
Bz 

do 

...do 

Bz... 
Bz  

Bz 

do 

do  

Caps  

do 

On  guides  (13A)  (13B)  (13C) 
(13D). 

C.S.No.l... 
C  S 

Cap  squares     

On  side  frames  

C.S.No.2... 
C  S  No  9 

do 

Catch  

In  foot  lever  bracket  
do               

C.S  

s  

Catch  pin  

Catch  spring  

do                           

s 

Catch  spring  plunger  

do  

Bz  

Clutch  spring 

On  elevating  shaft  
do  

do                   

Sp.  S  
F  S  

C.S     . 

Clutch  spring  adjusting 
nut. 
Clutch  spring  plate  

Collar 

For  pipe  connection         .  . 

s 

....do... 

On  piston  rod      

F.S 

.      do              

On  traversing  handwheel 
shaft. 
On  lock  bar        

s 

do  

s... 

Collar  nut                 .... 

On    elevating   handwheel 
shaft, 
do                     

F.S 

....do  

F.S. 

Core  hole  cover 

C  I 

Counter    recoil    springs 
(outer). 
Counter   recoil    springs 
(inner). 
Covers 

On  spring  rod  

Sp.  S... 

....do  

On  side  frames              ... 

Sp.S  

s 

Cover 

On  pedestal  bracket 

C  S 

do               

For  elevation  quadrant  
Between  guides 

Cotton  duck. 
F.S.No.2 

Crosshead 

....do  

do  

F.S.No.2... 

Cylinder  (right)  .   ... 

In.  side  frames              .... 

C.S.No.2 

Cylinder  (left) 

do 

C.S.No.2... 
Bz.No.4.,.. 
F.S.No.3... 
F.S.No.3... 
Bz  

Cylinder  heads  

In  cylinder  (13Y2)  (13Z2)  .  .  . 
do  

do 

Cylinder  plugs  (small)  .  .  . 
Cvlinder  plugs  (large) 

Direction  plate  (clamp)  .  . 
Direction  plate  (elevate)  . 
Direction  plate  (depress)  . 
Distance  ring. 

On  hand  nut.        

On  elevating  handwheel  . 

Bz       .  . 

do  

Between  racer  and  base  ring 
With  carriage 

Bz  
C.S  

Double  wrench 

F.S  

do 

In  armament  chest 

F.S 

do 

.do  

F.S... 

do 

do    . 

F.S  

do 

do 

F.S 

....do  

do  

F.S  

31 


Names  of  parts  of  12-inch  mortar  carriages,  model  of  1896  Mi  and  model  of  1896  Mil, 
their  piece  marks,  location,  and  material  of  which  they  are  made— Continued. 

12-INCH  MORTAR  CARRIAGE.  MODEL  OF  1896  Mi— Continued. 


Piece 
mark. 

No. 

Name  of  part. 

Location. 

Material. 

Remarks. 

N20E 
N20A 

sc 

11B 
5J 
N20H 

U46F1 
N20J 

13N1 
13T1 

4 
2 
2 
2 
2 
1 
2 
1 
1 
1 
1 

1 
1 
1 
1 
1 

1 
1 

1 

1 
1 

1 

1 
1 
1 

1 
1 
1 
2 

1 

Dowels 

For  side  frames 

S    . 

In  4  sections. 

Right.  For  Mi  car- 
riage. 
Left.    For  Mi  car- 
riage. 

Complete,   includ- 
ing handle. 
Do. 

For     Mi     carriage 
only. 
For    Mil    carriage 
only. 

Pinion  and  gear  to- 
gether. 

For  Mi  carriages. 

In  2  parts. 

Used   where 
needed. 

Do. 

For     Mi    carriage 
only. 
With  2  crown  nuts. 
For  model  of  1896 
Mil  only. 
For  model  of  1896 
Mi  only. 

For  model  of  1896 
Mn  only. 
Do. 
Do. 

2  large,  10  small. 

do 

For  azimuth  pointer  

S... 

....  do  

For  right-hand  scale  (N20B) 
For  left-hand  scale  (N20M). 
In  pedestil  bracket 

Br  

Br 

do 

Drain  plugs  
do 

S  

In  emptving  coupling 

W   I 

Drip  pans 

For  stuffing  boxes 

S  

Dust  guard  (complete).  .  . 
Elevating  gear 

Inside  racer 

s 

On  elevating  shaft 

Bz.No.  4.... 

F   S 

Elevating-gear  bushing.  . 
Elevating       hand  wheel 
shaft  bracket. 
do 

do 

On  top  carriage 

C.I   

do 

C  I 

Elevating       hand  wheel 
shaft  pinion. 
Elevating       handwheel 
(right). 
Elevating       handwheel 
(left). 
Elevating       hand  wheel 
shaft. 
do 

On    elevating    handwheel 
shaft. 
On  handwhee'  shaft 

F.  S.  No.  2.. 
S         

..   .  do.. 

s  

In  top  carriage 

F.  S.  No.  2.. 
F.  S.  No.  2.. 

...do... 

Elevating  idler  gear             ^^  idlpr  r>in 

Bz  No  4 

Elevating    intermediate 
gear. 
Elevating    intermediate 
bracket, 
do 

On  elevation  intermediate 
pin. 
On  top  carriage 

F.S.  No.  2.. 
C.I  

do 

C   I 

Elevating    intermediate 
pin. 
Elevating  pinion 

In  top  carriage  

F.S.  No.  3.. 
F.S.  No.  2.. 

On  elevating  shaft 

Elevating  rack 

On  mortar 

C.S 

Elevating  shaft 

In  top  carriage 

F.  S.  No.  3.. 

Elevation  pointer  (right) 
Elevation  pointer  (left).  . 
Elevation  stop 

On  top  carriage 

Bz 

do 

Bz 

....  do.. 

Bz.  No.  3 

Emptying  coupling 

On  equalizing  pipe  
Under  cylinders 

F.S.  No.  2.. 

s 

Equalizing  pipe  
Equalizing  pipe  bracket.  . 
Filler  piece 

do 

W  I 

On  racer 

s. 

do 

For  elevation  lock.  . 

s... 

do                                  I  do  

s 

1 

1 
2 

16 

1 
4 
4 
1 
1 
1 
5 
5 
1 

2 
2 

2 

2 
2 

2 
2 
4 
2 
12 

2 

....do    . 

Between  scale  (N20M)  and 
elevating  rack. 
In  armament  chest 

Bz  

Filling  funnel 

c 

Filler  pieces 

Between  scale  (N20M)  and 
elevating  rack. 
On  floor  plate 

•Bz  

Bz 

Floor  instruction  plate... 
Floor  plates 

On    azimuth    circle    and 
angles. 
In  armament  chest  

C.I         .   .  . 

File  card  

Commercial. 
Bz  

Bz.No.  4... 
C.  S.   .       .   . 

Followers 

In  cylinder  heads  (13X1).  .  . 
For  pipe  connection 

do 

Foot  lever  bracket 

In  foot  lever  bracket 

do 

On  racer 

C   S 

Foot  lever  pin 

In  foot  lever  bracket 

s  

Friction  disk  (inner)  
Friction  disks  (outer). 

On  elevating  shaft 

C.  I 

do  

BZ.NO.  4.... 

C.I 

Friction  filler  piece 

On    elevation    handwheel 
shaft. 
In  lever  on  elevation  rack  .  . 
In  top  carriage 

•Fulcrum  bolts    . 

s  

Fulcrum  bushings 

Bz.  No.  3.... 
Bz.No.  3.... 

do  

....  do  

Fulcrum  pins 

In  side  frames 

F   S 

do  

....  do  

F.S.  No.  2.. 
F.  S.  No.  2 

Fulcrum  pin  washer  
Fulcrum  washers  

On  fulcrum  pins 

On  top  carriage  

Bz.  No.  3... 

Gaskets  

For  plugs  (13P) 

F.  V.  F 

do 

For  plugs  (13U2) 

c 

do  

For    plugs     in    cylinders 
(13Y2)  (13Z2).      ' 
Under      cylinder      heads 
(13X1). 

C  

do 

F.  V.F  

32 


Names  of  parts  of  12-inch  mortar  carnages,  model  of  1896  Mi  and  model  of  1896  Mil, 
their  piece  marks,  location,  and  material  of  which  they  are  made — Continued. 

12-INCH  MORTAR  CARRIAGE,  MODEL  OF  1896,  Mi— Continued. 


Piece 
mark. 

No 

Name  of  part. 

Location. 

Material. 

Remarks. 

U55FA 

1 

Gland  wrench  

In  armament  chest  

S... 

1 

Graduation  strip  

On  azimuth  circle 

Rr 

In  8  sections 

13A 
13B 

1 
1 

Guide,  front  (right)  
Guide,  front  (left) 

On  cylinders  (13Y2)  
On  cylinders  (13Z2) 

C.S.  No.  1. 
C.  S.  No.  1 

13C 
13D 

1 
1 

Guide,  rear  (right)  
Guide,  rear  (left)  

On  cylinders  (13  Y2)  
On  cylinders  (13Z2) 

C.  S.  No.  1. 
C.  S.  No.  1 

1 

Hand  nut 

On    eJevating    handwheel 

S 

1 

Hinge  . 

shaft. 
For  azimuth  pointer  cover 

Bz.    . 

] 

Idler  pin 

In  top  carriage 

F.  S.  No  2 

8 

Keys... 

In  distance  ring 

S... 

9 

do 

In  fulcrum  pin 

S 

For  side  frames   ^ 

4 

do  .. 

Under  side  frames.  .  . 

S... 

^ 

..  .  do 

In  elevating  gear 

S. 

Riveted  in  ~5 

2 

do 

In  elevating  intermediate 

s 

4 

do 

gears. 
In  elevating  shaft 

S.  . 

S 

....  do 

In    elevating     handwheel 

s  

1 

do 

shaft. 
In    traversing    handwheel 

s 

2 

do 

shaft. 
In  vertical  traversing  shaft 

s... 

N20M1 

Left-hand  scale 

On  elevating  rack  

Monel  metal. 

UN 

Lever 

On  bracket  on  top  carriage 

F.  S... 

11M 

Lever  pin 

For  elevation  lock 

8 

11R 

I  ever  rest 

....  do 

F.  S... 

I  id 

For  azimuth  pointer 

Bz 

U47S 

Lifting  hooks 

In  armament,  chest. 

S... 

13Q1 

Liner  (right) 

On  crossheads  (13Q1) 

Bz 

13R1 

Liner  (left) 

On  crossheads  (13H1) 

Bz... 

13J1 

Liner.  .  . 
..    do 

On  crosshead  (13G1)  (13H1) 
On  spring  guide  rods  .     .   . 

Bz  
Br... 

11L 

Link 

For  elevation  lock 

S... 

11F 

Lock  bar 

In  bracket  on  top  carriage.  . 

F.  S.  No.  3.. 

no 

F   S  No  3 

Lower  brake  lever 

In  bracket 

C.S. 

Lower  brake-lever  stop 

For  traversing  brake 

S.... 

Lower  toggle  lever 

On  lower  brake  lever 

C.  S.   .       . 

On  traversing  handwheel 

Bz 

Name  plate  (No  2) 

On  top  carriage 

Bz  

13L 

2 

In  cylinders  (13Y2)  (13Z2) 

Bz 

13BA1 

? 

Nuts... 

In  crossheads  (13G1  )  (13H1  )  . 

F.  S.  No.  2.. 

5 

do 

For  spring  guide  rods  

S  

2.75  thick. 

5 

do 

...  do  

S..., 

1.5  thick. 

9 

.  .  do 

On  vertical  traversing  shaft. 

s  

9 

do 

For  toggle  pin 

s 

1 

do 

On  upper  toggle  link 

r.  s  

U46A 

2 

Oilers  (half-pint) 

In  armament  chest 

s 

Commercial. 

U46B 

1 

Oilers     (locomotive      1 

do 

s  

Do. 

J 

quart). 
Oil  pipe 

In  racer 

Br 

For  inside  of  dis- 

5F 

1 

do 

....do  

Br  

tance  ring. 
For  outside  of  dis- 

5G 

1 

do 

do 

Br... 

tance  ring. 
For  pintle. 

1 

do 

In  pedestal  bracket  

Br  

CT7- 

2 

Bz 

1 

In  racer 

Bz  

5D 

2 

Oil-pipe  strap 

On  racer       

S  

Qop 

9fi 

Bz 

Q3K 

12 

do 

Hz         

13M 

4 
j 

Pad:  ing  rings  

On  followers  (13N1)  
On  racer 

Bz  

r.  s  

In  halves. 

13  JA 

14 

Pieces 

Under  caps  (13F)  

Balata  

Pact  of  buffer. 

§ 

Pins 

For  bushings  on  top  car- 

Bz   

0.25     diamond 

2 

do 

riage. 
In  elevating  intermediate 

S  

driven. 
Driven. 

4 

do 

gears. 
do                      ... 

Bz... 

0.25  by  0.625  driven. 

4 

do 

do  

Bz  

0.25  by  0.75  driven. 

3 

do 

In    elevating     handwheel 

Bz  

0.25  by  0.875  driven. 

do 

shaft  bracket  (right). 

Bz 

0.25  by  1.25  driven. 

9 

do 

shaft  bracket  (left). 
For  brake  shoes             .   ... 

S  

do 

s  

1 

Pinion... 

On  vertical  traversing  shaft. 

Bz  

33 


Names  of  parts  of  12-inch  mortar  carriages,  model  of  1896  Mi  and  model  of  1896  Mil, 
their  piece  marks,  location,  and  material  of  which  they  are  made — Continued. 

12-INCH  MORTAR  CARRIAGE,  MODEL  OF  189G  Mr— Continued. 


Piece 
mark. 

No. 

2 
2 
1 
1 
1 
2 
12 
2 
4 
3 

4 
1 
1 
1 
1 
24 
2 
3 
1 
24 
32 
2 
2 
72 
144 

4 
11 
2 
32 

30 

2 
1 
3 

2 
2 

2 

2 
2 
16 
2 
12 

4 

1 
2 
15 
2 
4 

2 
1 
1 
1 

2 
15 
1 
1 

2 
2 
1 

1 

1 

1 
1 

Name  of  part. 

Location. 

j 
Material. 

Remarks. 

13DA 
13AA 
U43AM1 

UK 
13GA 
13HA 
13U2 
13P 
13  E 

5H 
N20B 

TJ44GA 

5B 
13FA 

N18C 
N20L 

N18A 

5E 
5E 

N20D 
N20F 

U44T 
U44  W 
U44HA 

N18F 

Piston 

On  piston  rod  (13AA)  
In  cylinders  (13Y2)  (13Z2).. 
With  carriage          ••  

Bz.  No.  4... 
F.  S.No.  3.. 

1  F.  S 

Part  of  buffer. 
Do. 

To  replace  equaliz- 
ing pipe. 

0.375  diamond. 
For  keys. 

0.5  by  1.125. 
0.5  by  1.125. 

0.25  by  0.68. 
0.25  by  0.75. 
0.25  by  0.75. 

0.5  by  1.5. 
0.5  by  1.25. 
0.5  by  1.375. 

1.375  by  2.625. 
0.25  by  0.625. 

0.375  by  0.75. 
0.375  by  0.75. 
0.25  by  0.375. 
0.125  by  0.3. 
0.25  by  0.5. 

1.5  by  3.  625. 
For    Mi    carriage 
only. 
1  right,!  left. 

4.'625. 
For  lower  follow- 
ers. 

For  floor  plate. 

For  elevating  pin- 
ion. 
For  elevating  hand 
wheel  shaft  pin- 
ion. 
For  thrust  collar. 
For  collar  nut. 
For  collar  on  lock 
bar. 

Piston  rod  .        

Piston-rod  wrench 

Pit  ladder  (complete)  
Pivot  stud 

Under  removable  floor  plate 
For  elevation  lock    

i  W  I 

s  

Plates 

Under  caps  (13F) 

s 

do 

do 

s 

Plugs  

In  cylinders  (13Y2)  (13Z2). 
do  

Bz.  No.  3... 
Bz  

do  . 

Plugs  (1  extra)  

In  cylinder  

Bz  

Quadrants,  gunners'  
Racer 

In  armament  chest  

On  base  ring 

C.  S.No.  2... 

s 

Reinforce  plate 

Under  floor  plate  

Removable  floor  plate.  .  . 
Right-hand  scale 

On  racer 

C  I 

On  elevating  rack  

Monel  metal  . 
G.W.H.P.. 

s 

Rings  packing 

In  cylinder  boxes 

Rivets 

For  reinforce  plate 

do 

In  elevating  gear  .  ... 

s 

Rod  (for  spanner  wrench) 
Screws 

In  armament  chest  

S  

For  bushings  in  side  frames. 
For  trunnion  cap  bushings  . 
For  azimuth  pointer 

Bz 

do  

Bz... 

.  .    do 

Br 

Screws,  countersunk  
....  do 

For  floor  instruction  plate.  . 

Bz... 

For  graduation  strip 

Bz 

do 

For  traversing  roller  bush- 
ings. 
For  core-hole  cover  (5A)  
For  removable  floor  plate  .  . 

Bz 

do 

Bz  

S 

do  

do 

For  elevation  stop 

s 

do  

For   liners    (13J1)    (13Q1) 
(13R1). 
For  liners  on  spring  guide 
rods. 
For  bracket  (N18D)  
For  filler  piece  (N20H)  .  .  . 

Br 

do 

Bz 

do 

Bz  

s 

do..  . 

do 

For    hinge     on     azimuth 
pointer. 
For  elevating  rack 

s 

Screws,  fillister  head... 
do 

s 

For  bracket  base 

s 

Screws,  headless 

In  elevating  intermediate 
gears. 
For  oil-pipe  strap  (5D) 

s 

Screws,  round  head 

Bz 

do 

For  oil-pipe  bracket  (5K) 

Bz 

do 

Cover  to  bushing 

Bz 

do 

For  direction  plate  (clamp). 
For  direction  plate  (elevate) 
(depress). 
For  elevation    pointer 
(N20E)  (N20A). 
For  catch  pin 

Br 

do 

Br  

Br 

do 

Screw  (special) 

Bz 

do 

For  right-hand  scale  (N20B) 
On  spring-guide  rods 

Bz 

Separators 

s 

Set  screws  

For  1  ulcrum  pin    

s 

Shaft  bracket  washer  
Side  frames  . 

Under  shaft  bracket 

s 

Onracer  

In  armament  chest.  .  . 

C.S.  No.  2.. 
F.  S     ... 

Spanner  wrench  

do  •    ;  do       

F  S 

do  '  do  

C  S  

Spline  screws 

Forscrp.w  CM1RA1 

s 

Split  pins  In  countersunk  bolts  

s 

do  On  lock  bar  (11F) 

s 

do                                             Fnr  linV  holt  nf  filAvafvirm 

g 

....do  

do 

For  stop  pin 

s 

For  fulcrum  nin 

s 

do  In  taper  pin  

s 

do  do  

s 

do  do  

s 

do  do 

s 

do  .  .                                   do 

g 

s 


34 


Names  of  parts  of  12-inch  mortar  carriages,  model  of  1896  Mi  and  model  of  1896 
their  piece  marks,  location,  and  material  of  which  they  are  made — Continued. 

12-INCH  MORTAR  CARRIAGE,  MODEL  OF  1896  Mi— Continued. 


Piece 
mark. 

No. 

Name  of  part. 

Location. 

Material. 

Remarks. 

11A 

U47BL 
U47BM 
U47BN 

U43AL 
11H 

N20C 

N20K 
U47BD 

U45AB 
U43Q 

2 
2 
1 

1 
2 
2 
2 
2 
4 
2 
4 
1 
2 
5 

5 
5 

5 
5 
2 
1 
1 
1 
4 
14 
1 
1 

1 
1 
1 
5 

1 
1 

1 

2 

1 

1 

1 

1 
24 
1 
2 

1 
1 
1 

1 
4 

1 
1 

1 
4 
12 

5 
5 
2 
2 
2 

2 
4 

1 
1 
3 

Split  pins 

For  fulcrum  bolt 

g 

1  right,  Heft. 

2.5  by  9.75. 
2  by;8.625. 

For    Mi    carriage 
only. 

Complete,       with 
handle. 

In  halves,  1  right, 
1  left. 

With  nuts. 

For  Mi  carriage. 
For  Mn  carriage. 
2  large,  10  small. 

Commercial. 

For  screw  driver. 
For  filling  plug. 

...do... 

For  vertical  traversing  shaft 
For  taper  pin,  on  traversing 
handwheel  shaft. 
For  upper  togglelink 

g 

....  do 

g 

.  .do 

g 

do 

For  upper  toggle  pin 

g 

do  

For  brake-link  upper  pin 

g 

do 

For  brake-link  lower  pin  .  .  . 

S 

do 

g 

.     .  do 

For  brake-shoe  pins 

g 

do 

For  upper  brake-lever  stop  . 
For  brake-lever  pins 

g 

do  ...      . 

g 

Spring 

Sp  S 

Spring-box  brackets  
Spring  compressor 
(screws). 
Spring  compressor 
(nuts). 
Springe  ompressor 
(washers). 
Spring  guide  rods  

Under  racer  

In  armament  chest  

C.I.  No.  2... 

s  

do  

s  

do  .-.  

C.I  

In  counter-recoil  springs.  .  .  . 
In  end  of  spring-guide  rods  . 

F.  S.  No.  2.. 
Bz  

Spring  guide-rod  plugs.  .  . 
Spring-rod  wrench 

With  carriage 

F  S 

Spring  washer 

On  brake  link  

S  

Stop  pin 

For  traversing  brake 

g 

Strap 

On  top  carriage  

In  top  carriage 

F.  S  
F.  S.  No.  3.. 
S  

Studs  with  nuts 

....  do  .  . 

For  spring  box  bracket  

Taper  pin 

In  elevating  pinion 

s  

do    

In    elevating    handwheel 
shaft  pinion. 
In  thrust  collar 

s  

do 

g 

do 

g 

do 

In  collar  on  lock  bar 

g   

.  .    do 

In  washer,  or  spring  guide 
rod. 
In  traversing  handwheel.  .  . 

g  

..  do  .. 

s..., 

do 

In  collar  on  traversing  hand- 
wheel  shaft. 
On   elevating   handwheel 
shaft  pinion. 

g  

Thrusrt  collar 

F.  S  

g 

Toggle  pin 

g  

Top  carriage 

On  fulcrum  pins 

C.  S.  No.  2.. 

Traversing     handwheel 
shaft. 
Traversing  handwheel.  .  . 

In  pedestal  bracket  

On  traversing  handwheel 
shaft. 

F.  S  

C.  S.  No.  3.. 
C.  I.  No.  1... 

F  S  No.  3 

In  pedestal  bracket          ... 

F.  S  

Trunnion  cap  bushing.  .  . 

In  top  carriage    

Bz.  No.  3... 
C.  S... 

In  bracket 

Upper  brake-lever  stop 

do        

S  

C  S 

c.s  

Vertical   shaft    bracket 
studs. 
Vertical  traversing  shaft  . 
Washer 

In  racer                 

s  

F.  S.  .. 

On   elevating   handwheel 
shaft, 
do           

S  

do 

Bz... 

do 

F.  V.  F  

do 

For     plugs    in     cylinders 
(13Y2)  (13Z2). 
On  spring  guide  rods      .  .  . 

L  

do 

S...     

do  

do 

do  

On  vertical  traversing  shaft. 
On  toggle  pin 

S  

s  

do 

s  

do 

Under    right-hand     scale 
(N20B). 
Under  bolts  (N20G)  

Bz  

do 

Bz  

Indur  a  t  e  d 
fiber. 
Bz.  No.  2... 
g      

Water  buckets 

Worm  wheel 

On  vertical  traversing  shaft  . 

rln 

F.  S  

g                    i 

35 


Names  of  ports  of  12-inch  mortar  carriages,  model  of  1896  Mi  and  model  of  1896  Mil, 
their  piece  marks,  location,  and  material  of  which  they  are  made — -Continued. 

12-INCH  MORTAR  CARRIAGE,  MODEL  OF  1896  Mil. 
[For  other  parts  of  Mil  not  listed  here,  see  list  of  Mi  parts:] 


Piece 
mark. 

No. 

Name  of  part. 

Location. 

Material. 

Remarks. 

j 

Angle  (in  4  sections) 

On  edge  of  racer          « 

S 

To  protec./  azimuth 

^ 

Bolts  countersunk  with 

Ladder  to  floor  plate 

S.   . 

circle. 
jO.75  by  2.125. 

1 

nuts, 
do 

Ladder  to  brace      

S... 

0.75  by  1.875. 

24 

Bolts  tap 

For  traversing  rack 

s 

0.75  by  3. 

16 

do  . 

Azimuth  circle  castings  to 

s  

0.75  by  2.5. 

?*> 

...do... 

bracket  . 
For  bushings  in  top  carriage 

Bz... 

0.5  by  1.125. 

4 

...    do 

For  foot-lever  bracket 

S... 

0.625  by  1.75. 

4 

do 

Bracket  to  racer 

s 

1  25  by  3 

s 

Bolts,  tap  (special) 

For  cap  squares  on  racer 

s... 

2  by  4.75. 

g 

Bolts  with  nuts 

Azimuth  circle  castings  to 

s  . 

1  by  2  5. 

4 

Bushings  (in  halves) 

intermediate  angles. 
In  bearings  on  racer 

Bz.No.  3 

2  right  2  left. 

4 

Cap  squares  

On  racer  

C.S.No.l... 

Do. 

1 

On  traversing  worm  shaft 

S.. 

1 

Core-hole  cover  

On  racer.  

C  I  

12  diameter. 

? 

Cylinder  head 

In  recoil  cylinders.  .  . 

BZ.NO.  4 

1 

Oil  pipe 

In  pedestal  . 

Br 

4 

Oil  tubes  (bent)  . 

In  racer  .  .  . 

Br... 

s 

Oil  tubes  (straight) 

....  do 

Br 

1 

Pedestal                  

On  racer 

C  I 

1 

Pedestal  cover. 

On  pedestal 

C.I 

9 

Pistons 

On  piston  rods 

F  S  No  3 

2 
1 

Piston  bushings  
Pit  ladder  (complete) 

do  

Under  removable  floor  plate 

Bz.No.4.... 

F.  S 

1 

Racer 

On  base  ring 

C  S  No  1 

? 

Recoil  cylinders 

In  bearings  on  racer 

C.S.No  3 

1  right  1  left. 

1 

Removable  floor  plate 

On  racer 

C  I 

4 

Screws,  countersunk  .  . 

Core-hole  cover  to  racer 

Bz 

0.5  by  1.5. 

11 

..  .  do 

Floor  plate  to  racer 

Bz 

0  75  by  2 

I9 

do 

In  racer  oil  holes 

Bz 

0  5  by  1 

80 

Screws,  countersunk 

Angle  to  racer 

s 

?4 

(special). 
Screws  ("special)  . 

For  bushings  in  racer 

Bz 

Split  pin 

In  taper  pin 

s 

Taper  pin..   .. 

In  traversing  pinion.. 

s 

Traversing  hand  wheel  .  .  . 
Traversing  pinion  . 

On  traversing  worm  shaft  .  . 
On  vertical  traversing  shaft 

C.I.  No.  2... 
Bz.  2. 

Complete,    includ- 
ing handle. 

Traversing  rack  

On  base  ring  

F.  S... 

In  6  sections. 

Traversing  worm  shaft  .  .  . 

In  pedestal  

S 

Vertical  traversing  shaft  . 

do  . 

F   S  No  1 

ELECTRICAL  EQUIPMENT. 

[On  drawings  12-12-21  and  12-13-11,  Plates  VII  and  XII,  are  given  the  locations  of  the  receptacles,  plugs, 
etc.,  on  the  carriages  and  the  lengths  of  slicked  reinforced  cord  and  armored  cable  required.  In  ordering 
parts  for  replacement,  the  piece  mark  given  in  the  left-hand  column  and  the  name  of  the  part  should  be 
stated.] 


E25M1 
E25M1 
E25M1 
E25M1 
E22L 
E21F 
E21J 
E22V 

T95C 
P57AE 
P57AF 
T96H 

T95J 
E22R 

1 
1 
1 
1 
1 
1 
1 
1 

1 
1 
1 
1 
4 

2 
2 

Base 

For  receptacle,  E25AB  
For  receptacle,  E25J1  
For  receptacle  E25H1 

Cond  
Cond 

For  110-volt  main. 
For  220-volt  main. 

For  magneto,  M.  A. 
Furnished  by  En- 
gineer Depart- 
ment. 
For  1896  Mi  only. 

0.75  by  1.625. 

do.... 

do 

Cond 

do 

For  receptacle'  E25AF  
For  junction  box,  E22N  .  .  .  . 
For  junction  box  E21T 

Cond  
Cond 

do 

do 

Cond 

do  ..     . 

For  junction  box'  E21U 

Cond 

do 

For  quadrant  lamp  bracket, 
In  bottom  of  well 

Cond 

Base  bracket 

F   S 

Boat  snap  hook 

On  mortar 

Comm  .  .  . 

s 

Boat  snap  hook  screw 
Body  

do 

For  terminal  tube  T96EA 

Bz 

Bolts,  foundation,  -with 
washers  and  nuts. 

Bolts,  hex  

For  magneto  bracket 

For  receptacle   bracket, 
T95F. 
For  quadrant  lamp  bracket, 
E22P. 

Bz 

Bolts,  tap... 

g 

Names  of  parts  of  12-inch  mortar  carnages,  model  of  ,1896  Mi  and  model  of  1896  J///, 
their  piece  marks,  location,  and  material  of  which  they  are  made — Continued. 


ELECTRICAL  EQUIPMENT— Continued. 


Piece 
mark. 

No. 

Name  of  part. 

Location. 

Material. 

Remarks. 

T95D 

3 

Bolts,  tap  

For  base  bracket  

S  

0.75  by  8;    6  std. 

E20C 

9 

do 

For  plug  box 

s 

nuts. 
0  25  by  0  875 

T91R 
T91R 

15 

9 

do  

do 

For  straps,  T91F  
For  straps  T91Z 

s  

s 

For  1896  Ml  only. 
0.5  by  1. 
For  1896  Mn  only 

T91R 

q 

....  do 

For  straps,  T91F 

s 

0.5  by  1. 
For  1896  Mil  only 

E22Q 

1 

Bracket 

For  quadrant  lamp  bracket 

Bz 

0.5  by  1. 

V23AM 

1 

Bushing  

E22P. 
On  plug  box  .  .  . 

Comm. 

0.75  by  0.5. 

E25\J 

1 

do 

For  cover  for  receptacle 

Cond 

E25AJ 

1 

do      . 

E25J1. 
For  receptacle,  E25H1 

Cond. 

T97P 

1 

Cable  terminal 

For  magneto  cable 

T97Q 

1 

do 

do 

E12X 

?, 

Cable  thimbles 

For  slicked  cord  . 

G.I. 

E13\J2 

1 

Candelabra  receptacle 

For  quadrant  lamp 

V.  A 

E13AJ2 

1 

do         '        r~ 

For  azimuth  lamp 

V  A 

E12NA 

? 

Candelabra  lamps  8C  P 

For  elevation  quadrant  and 

Comm 

E23L 

Chain 

azimuth  pointer. 
For  receptacle  E25AF 

Br.   . 

No.  2,  plumber's. 

E23L 

1 

...    do 

For  receptacle  E25H1 

Br 

Do 

E23L 

1 

do. 

For  receptacle,  E25AB 

Br... 

Do. 

E23K 

1 

Chain  pivot 

do 

Br 

E23K 

1 

do... 

For  receptacle,  E25AF 

Br... 

E23K 

1 

do    . 

For  receptacle  E25H1 

Br... 

E22Y 

9 

Connector  links 

For  quadrant  lamp  bracket 

S.C 

E21K 

9 

Connector  strips 

For  junction  box  E21T 

S.  C. 

E25K1 

9 

..     .do 

For  receptacle  E25I1 

S.C 

E25K1 

? 

do 

For  receptacle'  E25AB 

S.C... 

E25K1 

9 

do 

For  receptacle  E25AF 

S.C. 

E21L 

1 

do 

For  junction  box  E21TJ 

s  c 

E21N 

? 

do 

do... 

S.C. 

E21M 

9 

...  .do 

For  junction  box  E21T 

S.C 

E25S3 

Contact  housing 

For  plug,  E25AA1 

Bz... 

E25T3 

1 

do 

For  plug  E25Z1 

Bz 

E25T3 

9 

do 

For  plug  E25AD 

Bz 

E25Q 

4 

Contact  screws  rd  hd 

do... 

Br.... 

0.138  by  0.125  A.  S. 

E25Q 

2 

...do. 

For  plug,  E25AA1 

Br... 

M.E.std. 
Do. 

E25Q 

9, 

do 

For  plug  E25Z1 

Br.. 

Do. 

E25P1 

4 

Contact  strips 

For  plug  E25AD 

C... 

E25P1 

? 

do 

For  plug  E25Z1 

C.... 

E25P1 

2 

..     -do 

For  plug  E25AA1 

C.... 

E25R2 
E25R2 

Contact  terminal... 
do 

do  

For  plug  E25Z1 

Cond  
Cond.. 

G25AC1 

do 

For  plug  E25AD 

Cond. 

E22AB 

Coupling 

For  quadrant  lamp 

Bz... 

E22AB 

-  .  .  -do 

For  azimuth  lamp 

Bz 

E25G 

Cover 

For  receptacle  E25AB 

Bz 

E25G 

do 

For  receptacle'  E25AF 

Bz  

E25E1 

do 

For  receptacle  E25H1 

Bz 

E22S 

do 

S.  B 

E21D 

1 

do 

E22P. 
For  junction  boxes    E21T 

Bz 

P65A2 

1 

do 

orE21U. 
For   cover   for  receptacle 

Bz  

E22C 

1 

...  .do 

E25J1. 
For  junction  box  E22N... 

S.  B  

1 

Expansion  hook 

In  bottom  of  well 

Comm  

0.375  by  6. 

1 

do 

do  

Comm  

0.375  by  3.5. 

T95E 

1 

Evebolt 

F  S. 

E22E 

1 

Gasket  

For  junction  box,  E22N  

S.  R  

0.062  thick. 

E23  \D 

1 

do 

S.  R 

Do. 

E23AD 

2 

do 

For  plug'  E25A.D 

S   R 

Do. 

E25D 

1 

do 

Forrecep'tacle  E25AB 

S.R  

Do. 

E25D 

1 

...  .do 

For  receptacle  E25J1  

S.  R  

Do. 

E25D 

1 

do 

For  receptacle  E25H1 

S.R... 

Do. 

E25D 

1 

do 

For  receptacle,  E25AF  

S.R  

Do. 

E23M 

1 

do 

do 

S.  R 

Do. 

E23M 

1 

do 

For  receptacle  E25H1 

S.  R  

Do. 

E23M 

1 

.do 

For  receptacle,  E25AB  

S.R  

Do. 

E22U 

1 

do 

For  quadrant  lamp  bracket, 

S.R  

Do. 

E22P. 

37 


Names  of  parts  of  12-inch  mortar  carriages,  model  of  1896  Mi  and  model  of  1896  Mn, 
their  piece  marks   location,  and  material  of  which  they  are  made — Continued. 

ELECTRICAL  EQUIPMENT— Continued. 


Piece 
mark. 

No. 

Name  of  part. 

Location. 

Materia  1. 

Remarks. 

E21C 

1 

Gasket 

For  junction  box,  E21T  or 

S.  R  

0.062  thick. 

E23AB1 

l 

Gland 

E21U. 
For  receptacle  E25J1 

Bz 

E25  YB1 

2 

do 

For  plug  E25AD    . 

Bz     

E23AB1 

1 

do 

For  plug,  E25AA1  

BK..:  

E23A.B1 

1 

do 

For  plug  E25Z1 

Bz        

E22.T 

1 

do 

For  junction  box,  E22N  .  .  . 

Bz  

E21Y1 

5 

do 

For  terminal  tube  E21Z 

Bz 

E25W 

9 

do 

For  terminal  tube,  E25AE 

Bz  

T96GA 

1 

Gland  nut 

For  terminal  tube,  T96EA  . 

Bz  

For  magneto,  M.  A 

E25V 

•> 

Gland  rings 

For  terminal  tube,  E25AE 

Bz     

T96FA 

1 

do 

For  terminal  tube,  T96EA  . 

Bz....  

Do. 

E21X 

-, 

do 

For  terminal  tube,  E21Z     . 

Bz     

E25U 

4 

For  plug  E25AD 

Br 

E25U 

9 

do 

For  plug,  E25AA1      

Br         

E25U 

2 

do 

For  plug  E25Z1 

Br 

E21A1 

1 

Junction  box 

For  junction  box,  E21T  or 

Bz  

E22X 

1 

Lamp  fit-tin01 

E21U. 
For  ouadrant  lamp 

Bi 

E22A1 

1 

Lamp  junction  box 

For  junction  box,  E22N  

Bz  

For  azimuth  lamp. 

E12Q1 

1 

Lamp  spring 

For  azimuth  lamp 

P   Bz 

. 

E12Q1 

1 

....  do 

For  ouadrant  lamp  

P.  Bz  

P65C1 

1 

Lid 

For  cover   for  recaptacle 

Bz 

1 

Magneto  type  M    V 

E25J1. 
Attached  to  magneto 

P73D 

1 

Magneto  cable  plug 

bracket. 
For  magneto  cable 

Furnishedjby~  En- 

77 A 

1 

Magneto  bracket 

Attached  to  wall   of  em- 

gineer      Depart- 
ment. 

E25N1 

1 

Mica 

placem°nt. 
For  receptacle  E25VB 

0.1875  by  2  by  0.062 

E25N1 

1 

do 

For  rcc3ptacle  E25I1 

thick. 
Do. 

E25N1 

1 

do 

For  receptacl3  E25H1 

Do. 

E25N1 

1 

do 

For  rec^ptacl^  E25  VE 

Do. 

E21H 

1 

do 

For  junction  box   E21T  or 

3.5    diameter    by 

E22BA 

1 

do 

E21U. 
For  junction  box  E22N 

0.031  thick. 
1.375  bv   1.375  by 

E22CA 

1 

do 

For  ouadrant  lamp  bracket 

0.062  thick. 
1.625  bv   2.375  by 

E25AM 

4 

Nuts,  hex 

E22P. 
For  receptacle,  E25AF 

Bz  "... 

0.062  thick. 
0.190  bv  0.2  thick, 

E25\M 

4 

do 

For  receptacl0  E25  \  15 

Bz 

0.375  flats. 
Do. 

E25AM 

4 

do 

For  receptacle,  E25H1 

Bz     

Do. 

E25\M 

1 

do 

For  receptacle  E25J1 

Bz 

Do. 

E22G 

4 

....  do 

For  ouadrantlamp  bracket 

Br         

0.190  by  0.125  high. 

E22G 

4 

...do 

E22P. 
For  junction  box  E22N 

Br.. 

Do. 

2 

.  .    do 

On  plug  chain 

Br 

Do. 

E21S 

16 

do 

For  junction  box   E21T  or 

Br 

Do. 

T95K 

2 

Nuts,  wing 

E21U. 
For     receptacle     bracket 

Bz  

For  1S96  Mi  only, 

1 

Packing 

T95F. 
For  terminal  tube  E25AE 

Flax 

0.375  std. 

5 

do 

For  terminal  tub^  E21Z 

Flax  

Square  Navy  type. 

1 

do 

For  receptacle  E25J1 

Flax 

Do. 

E22K 

1 

...do 

For  junction  box,  E22N 

Flax... 

Do. 

E25AK 

1 

Pin 

For  cover  for  receptacle 

H.  R 

.    E25AK 

1 

...    do 

E25J1. 
For  receptacle,  E25H1 

H.  R    

E20B 

Plug  box 

On  side  frame  1896  Mi  on 

Furnished  bylEn- 

E23AC1 

2 

Plug  caps       

racer,  1896  Mn. 
For  plug,  E25AD  

Bz... 

gineer  &  Depart- 
ment. 

E23AC1 

1 

do 

For  plug,  E25Z1 

Bz     . 

E21E 

1 

Plumber's  chain 

For  junction  box   E21T  or 

Br 

5  long. 

E20A 

1 

Portable  lamp  and  cable. 

E21U. 
For  plug  box,  E20B  

FurnishedJbvlEn- 

1 

Pulley  block  double 

For  base  bracket 

Comm 

gineer      Depart- 
ment. 
0.375  by  1.25  sheave 

E25A 

1 

Receptacle  box 

For  receptacle  E25AB 

Bz       

swivel  eye. 

E25B1 

1 

do 

For  receptacle  E25J1 

Bz 

E25A 

1 

do  

For  receptacle,  E25Hi 

Bz  

E25AG 

1 

...do... 

For  receptacle,  E2.">.\  F.  .  . 

Bz... 

38 


Name*  of  parts  of  12-inch  mortar  carriages,  model  of  1896.  Mi  and  model  of  1896  J///, 
their  piece  marks,  location,  and  material  of  which  they  are  made — Continued. 

ELECTRICAL  EQUIPMENT— Continued. 


Piece 
mark. 

No. 

Name  of  part. 

Location. 

Material. 

Remarks. 

E25G 

1 

Receptacle  bracket  

For     receptacle     bracket, 

Bz 

For  1896  Mi  only 

E23J 

1 

Receptacle  cap  

T95F. 
For  receptacle,  E25J1  

Bz... 

E23J 

1 

do  

For  receptacle  E25H1 

Bz 

E23J 

1 

do 

For  receptacle  E25AF 

Bz 

E23J 

1 

do  

For  receptacle  E25AB 

Bz     . 

E12P3 

1 

Reflector 

For  azimuth  lamp 

S   B 

E12P3 

i 

do  

For  quadrant  lamp 

S.  B 

P65F 

1 

Ring                .        ~~ 

On  plug  chain 

Corn  rn 

Galvanized 

1 

Sash  chain  

For  receptacle  stud  T95V 

Br.   . 

For  1896  Mil  only 

..  .  do 

On  boat  snap  hook 

Comm 

4  inches  of  0.187 
chain. 
Brass  No  3 

E22B 

2 

Screws,  fil.  hd  

For  junction  box  E22N..  . 

S  

0.375  by  1  std. 

T95H 

? 

do 

For    receptacle     bracket 

Bz 

For  1896  Mi  only 

E25C 

9, 

..  do 

T95F. 
For  receptacle  E25H1 

S 

0.5  by  1.125  std. 
0.375  by  0  875  std 

E25C 

7, 

do 

For  receptacle  E25AB 

s 

Do 

E25F 

8 

Screws  flat  fil  hd 

For  receptacle'  E25J1 

Br 

0.164  by  0.45  A.  S. 

E25F 

9, 

..  do 

For  receptacle  E25AB  base 

Br 

M.  E.std. 
Do. 

E25F 

4 

do 

For  receptacle  E25H1  cover 

Br 

Do 

E25F 

?, 

do 

For  receptacle  E25AF  base 

Br      

Do. 

E25F 

9, 

do 

For  receptacle  E25H1  base 

Br 

Do. 

E25F 

4 

do 

For    receptacle      E25AF 

Br  

Do. 

E25F 

4 

do 

cover. 
For    receptacle     E25AB 

Br  

Do. 

E22T 

6 

do 

cover. 
For  quadrant  lamp  bracket 

Br 

0  190  by  0  5  A.  S. 

E22M 

? 

do 

E22P. 
For  junction  box  E22N 

s 

M.  E.  std. 
0  190  by  0  562  A.  S. 

E22W 

4 

do 

For  quadrant  lamp  bracket 

g 

M.  E.  std. 
0  190  by  0  625  A.  S. 

E23C 

4 

do 

E22P. 
For  cover  for  receptacle 

Br 

M.  E.std. 
0  164  by  0  437  A.  S. 

E21B 

? 

.  do 

E25J1. 
For  junction  box  E21T  or 

s 

M.  E.  std. 
0  375  by  1  std. 

E22D 

6 

...    do 

E21U. 
For  junction  box  E22N 

Br 

0  164  by  0437  A.  S. 

P45BB 

1 

do 

On  terminal  for  grounG.  con- 

Br 

M.  E.  std. 
0  25  by  0  5  std. 

E21G 

? 

do 

nection. 
For  junction  box  E21T  or 

Br 

0  190  by  0.45  A.  S. 

2 

Screws  rd  hd            

E21U. 
do 

Br          ..... 

M.  E.  std. 
0  190  by  0.2  A.  S. 

2 

do 

On  plug  chain 

Br          

M.  E.  std. 
0  190  by  0.375  A.  S. 

2 

do 

On  receptacle  stud  T95V 

Br        

M.  E.  std. 
For  1896  Mn  only, 

2 

Split  pins 

do 

Br 

0.164  by  0.25  A.  S. 
M.  E.  std. 
For  1896  Mn  only, 

1 

do 

On   cover   for   receptacle 

0.156  by  1. 
0  125  by  1  5. 

P65D1 

1 

Spring 

E25J1. 
do 

s 

0  040  wire. 

T95A 

1 

do 

Br 

No     13    B.    &    S. 

T91Z 

2 

Straps      

well. 
Armored  cable  to  carriage  .  . 

S  

gage. 
For  1896  Mn  only. 

T91F 

q 

....  do 

do 

S       

Do. 

T91F 

]«> 

do 

do 

s 

For  1896  Mi  only. 

T95W 

? 

Studs 

For  receptacle  stud  T95V  . 

Bz  

For  1896  Mn  only. 

E25X 

9 

Stuffing  tubes 

For  terminal  tube  E25AE 

Bz          

P45AN 

1 

Terminal 

c 

E25L1 

9 

Terminal  clips 

For  receptacle  E25H1 

p   Bz       

E25L1 

2 

do               

For  receptacle,  E25.T1  

P.  Bz  

E25L1 

9 

do                         .  . 

For  receptacle  E25AF 

P.  Bz       

E25L1 

9 

do 

For  receptacle  E25AB 

P  Bz 

E25F 

9 

Terminal  screws  flat  fil. 

For  junction  b'ox  P22N     .  . 

Br  

0.190  by  0.875  A.  S. 

E21P 

fi 

do                  

For  juuction  box,  E21T  or 

Br  

M.  E.  std. 
0.190  by  0.75  A.  S. 

E22Z 

4 

do 

E21U. 
For  quadrant  lamp  bracket, 

Br        

M.  E.  std. 
0.190  by  0.687  A.  S. 

E210 
FU 

9 

do 

E22P. 
For  junction  box  E21T  or 

Br  

M.  E.  std. 
0.190  by  0.875  A.  S. 

E21U. 

M.  E.  std. 

39 


Names  of  parts  of  12-inch  mortar  carriages,  model  of  1896  Mi  and  model  of  1896  Mn. 

their  piece  marks,  location,  and  material  of  which  they  are  made — Continued. 

ELECTRICAL  EQUIPME NT-Continued. 


Piece 
mark. 

No. 

Name  of  part. 

Location. 

Material. 

Remarks. 

E25AL 

4 

Terminal  screws,  flat  fil. 

For  receptacle,  E25J1  

Bz  ... 

0  190  by  0:85  A    S. 

E25AL 

4 

hd. 
do  

For  receptacle,  E25AF  

Br... 

M.  E.  std! 
Do. 

E25AL 

4 

do 

For  receptacle,  E25H1   ^ 

Bz 

Do 

E21W 

5 

Terminal  tubes  

For  terminal  tube,  E21Z  .  .  . 

Bz... 

E21R 

8 

Washers  . 

For  junction  box,  E21T  or 

Br 

0  375  diameter  by 

E22H 

2 

do  . 

E21U. 
For  junction  box  E22N 

Br 

0.031  thick,  0.193 
hole. 
0  375  diameter  by 

T95B 

o 

Wire  hooks 

On      spring      supporting 

F  S 

0.031    thick.  0.2 
hole. 

slicked  cord. 

AMMUNITION  TRUCK,  TYPE  12  M.  B. 
[2  per  carriage.] 


A3D 
A3C 

1 
1 
44 
1 
4 
1 
1 
1 

1 
2 
2 
1 
1 
2 
2 
1 
1 
2 
2 
2 
2 
2 
2 
1 
1 
2 
2 
4 
2 
2 
1 
1 
1 
1 

4 
1 
2 
1 
2 
4 
100 
4 
2 
1 
1 

2 
2 
1 
2 
2 
2 
2 
2 
2 

2 

2 

Adjustable  stop 

On  bndv 

s 

0.5  by  1.35. 

Hardened. 
1  right,  1  left. 

With  rubber  tires. 

1  right)  1  left. 

2  right,  2  left. 
0.5  by  0.75. 

For  Nos.  1-62,  inch 
For    No.    62    and 
above. 
0.375  standard. 

No.  14. 

0.25. 
1  right,  1  left. 

Axle                                  ;  Under  front  leg 

W  I 

Balls  For  caster  bearings 

s 

Body.                                  Riveted  on  top  of  angles 

C  S 

Bolts,  with  nuts              .    For  brake-shaft  brackets 

s 

Brake  lever                         On  brak-A  shaft 

s 

Brake-lever  guide  

On  rear  leg 

s 

Brake-lever  spring 

Between  brake  lever  and 
crosstie. 
In  brake-shaft  bracket 

s 

Brake  shaft  ..  ' 

s 

Brake-shaft  brackets  
Brake  shoes 

On  front  and  rear  ties  

Bz... 

On  brake  shaft  
In  front  of  body 

C.S  

s 

Buffer  pin 

Buffer  spring 

.do 

s 

Bushings 

Tn  r>astpr  whppls 

Bz 

Bz 

Cap  .  .                                 1  On  buffer  pin 

Bz 

Cap  pin  i  In  buffer  pin 

s 

Casters                                In  caster  brackets 

Bz 

Caster  ball  bearings             On  caster 

S   .. 

Caster  brackets 

Riveted  to  rear  leg  

Tn  caster  bracket 

C.S  

W.  I 

Caster  pins 

Caster  roller  pins                In  caster 

W   I 

Caster  wheels                            do 

g 

Crosstie  On  front  and  rpar  tips 

s 

Front  leg 

Under  body 

s 

Front  and  rear  ties 

Between  front  and  rear  legs. 
In  handle-bar  brackets  
Riveted  to  legs          .   . 

s.  ... 

Handles 

White  oak.. 
W.  I.. 

Handle-bar  brackets.  .  . 
Headless  bolts 

For  brake  shoes 

s 

Keys 

do 

s 

do... 

For  brake  lever 

s 

Loading  tray  

s.  s... 

Name  plate 

On  body                                  B/, 

do 

do  . 

S  B 

Oil  plugs 

In  wheels  and  shaft  bracket  . 

Bz 

Pin 

s 

Pins,  escutcheon 

For  name  plate,  A3D  Br  

Under  bod  v...                     ..    S.__. 

Rear  leg 

Rings  For  caster  ball  bearing           C 

Rivets                                            ~Fnr  <5hnt-trav  shop.                        W    T 

do 

For  body  and  angles,  etc  .  .  .   W.  I  

In  handle-bar  brackets            S 

Screws,  No.  10,  wood  
Screws,  round  head  
Set  screw  .  . 

For  name  plate,  A3C  Br  

For  brake  lever  .                      s 

Shot-tray  shoe  

Riveted  to  front  of  loading 
tray. 
Rivp.fprl  to  bndv  and  Ip.srs 

Bz  

Side  braces.. 

8 

Split  pins                          '  In  cap  pin                               S 

do  In  buffer  pin                          .  S 

do.                                 For  adjustable  stop  pin           S 

do  .    For  caster  nins.                          S 

do  

do 

For  caster  roller  pins               S 

Tn  avlp                                                S 

do  In  bnffp.r  r>in  .      '                        fi     . 

Transoms  .  . 

Riveted  to  front  and  rear 
legs. 
On  axlp. 

s 

Washers 

s 

Wheels..                                     do                                       C  S 

Names  of  parts  of  12-inch  mortar  carriages,  model  of  1896  Mi  and  model  of  1896  J///, 
their  piece  marks,  location,  and  material  of  which  they  are  made  —  Continued. 


SHOT  TONGS. 
[1  per  carriage.] 


Piece 
mark. 

No. 

Name  of  part. 

Location. 

Material. 

Remarks. 

A8G 
ASH 
A8L 
ASM 
AST 

ASK 

2 
3 
1 

2 
2 
1 
1 

Claw,  inner 

Opposite  outer  claw  . 

S 

In  two  parts. 
Do. 

Riveted  to  claw. 
Do. 

Claw  outer 

Pivoted  on  center  pin             S 

Dog... 

do  S  

Pin,  center 

In  claws  and  dog                  :  S 

Pin,  shackle  

In  shackle  and  outer  cluw  .  .  . 
Between  two  parts  of  outer 
claw. 
Between  two  parts  of  inner 
claw. 
On  shackle  pin  and  outer 
claw. 
In  shackle  pin 

S  

Separators 

s 

do  
Shackle  

S... 

s  

Split,  pins 

s 

do  

Spreader 

In  center  pin  S  

In  outer  claw                            S 

do  

In  inner  claAv  S  

LANYARD  ATTACHMENT. 


N17G       2 
N17L 
N17A 
N17B1 
N17D 

N17H1 
N17K1 

N17F 

N17E 
N17J  1 

Bolts,  with  nuts  
Bridle  ring 

For  pulley  bracket  (N17K1). 
Cn  lanyard  (N17D) 

S  

Including  2  hooks. 

0.25  by  0.375. 

For  pulley. 
For      button 

(N17A). 

Button  
Hook 

On  end  of  lanyard  (N17D1)  . 
do 

C  S 

s 

Lanyard  (complete)  
Pulley 

Through  racer  to  breech  of 
mortar. 
In  pulley  bracket  (N17K1). 
On  pit  ladder  

Hemp 

Bz 

Pulley  bracket  

Bz... 

Screws,  countersunk.  .  .  .  . 
Split  pin 

For  washer  (N17J)  
In  pulley  bracket  (N17K1). 
.do  .   .  . 

S  

s 

Washer 

s  

do 

On  racer 

C  S 

ELEVATION   QUADRANT. 
[Details  marked  *  apply  to  quadrants  Nos.  1  to  217,  inclusive,  only.] 


R19T 

I 

On  bubble  housing  (R19U) 

Bz 

R19C 

1 

Arm  sector 

In  arm  (R19T1) 

Bz.. 

R19CA 

1 

In  worm  sector  (R19Z) 

P   Bz 

R19Q 

1 

Arm  stop  screw 

In  bracket  (R19R)  

S... 

R19R 

1 

Bracket 

On  mortar  trunnion 

Bz 

R19FA 

1 

On  arm  (R19T) 

Bz 

R19U 

1 

Bubble  housing 

On  bracket  (R19R) 

Bz    . 

R19X 

1 

In  bubble  housing  (R19U) 

Bz 

R19EA 

1 

Bubble-housing   retain- 

do 

S  

R19N 

1 

ing  screw. 

do 

Bz 

R19E 

1 

Level  vial 

do 

Glass  

R19J 

1 

Locking  screw  (upper) 

In  worm  (R19L) 

s 

R19K 

j 

do 

s 

R19B 

1 

Micrometer 

do 

G.  S  

R19P 

j 

On  micrometer  lead  (R19G) 

G    S 

R19F 

1 

For  micrometer  (R19P) 

s 

R19G 

1 

screw.* 

do 

R19D 

1 

Micrometer       retaining 

In  arm  (R19T)  

s  

R19V 

1 

screw. 
Index 

Under  micrometer  (R19B).. 

s... 

R19M 

1 

Index  retaining  screw 

In  arm  sector  (R19C)  

s... 

1 

Pin 

In  worm  (R19L) 

s    ...  . 

0.04  bv  0.12  driven. 

R19W 

2 

For  bracket  (R19R) 

Bz 

Required  by  Cl.  12, 

R19BA 
R19AA 

1 
2 

Screw  spring*  

For  micrometer  (R19P)  .... 
For  bracket  (R19R) 

P.  Bz  
Bz 

Div.  12  and  13. 
Required  by  Cl.  12 

R19A 

1 

Sector  spring  

In  worm  sector  (R19Z)  

P.Bz  

R19DA 

1 

Washer 

On  worm  (R19L)  

S  

R19S 

2 

Washers  * 

For  micrometer  head 

G.  S  

R19L 

1 

(R19G). 
In  arm  sector  (R19C) 

s 

R19H 

1 

Worm  nut 

On  worm  (R19L) 

Bz... 

R19Z 

1 

In  arm  (R19T) 

Bz 

41 


Names  of  parts  of  12-inch  mortar  carriages,  model  of  1896  Mi  ana  "model  of  1896  Mil, 
their  piece  marks,  location,  and  material  of  which  they  are  made — Continued. 


GREASE   CUP. 
[2  per  carriage.] 


Piece 
mark. 

No. 

Name  of  part. 

Location. 

Material. 

Remarks. 

A2A 

A2B 
A2D1 

A2E2 
A2J 
A2H 

A2F 

A2C1 

1 

1 

1 
2 

i 

! 

i 
i 

Body 

Screwed  into  carriage  ....  

Bz... 

0.125  by  0.5  driven. 

Cap  

On  upper  end  of  body  (A2A). 
•  Underneath  plunger  (A2E1). 
Underneath  body  (A2A) 

Bz....,  

CUD  leather 

Leather  
C. 

Gaskets 

Pin  

Plunger 

In  plunger  (A2E1)                  ,  Bz 

In  body  (A2A)                        .    Bz.. 

Plunger  nut 

On  plunger  (A2E1) 

Bz 

Screw 

Cup  leather  to  plunger  

Bz... 

Split  pin 

For  plunger  and  plunger  nut. 
Between    cap    (A2B)    and 
plunger  (A2E1). 
Underc'up  leather  (A2D1) 

s 

Spring  

s  

Washer 

B7 

1 

Approximate  weights  of  principal  parts  of  12-inch  mortar  carriages,  model  of  1896  Mi 
and  model  of  1896  Mil,  as  prepared  for  shipment. 


Number 
of  loose 
pieces, 
crates, 
or  boxes. 

Contents  of  each  package. 

Weight 
(pounds). 

Remarks. 

Num- 
ber of 
parts. 

Name  of  parts. 

1 
1 
1 
1 

1 

2 
4 
1 

2 

1 

1 
1 
4 
1 

Box  

8 
4 

4 
1 

40 

3 
4 
1 

1 

2 

1 
\ 

6 
1 

Azimuth  circle  brackets  

690 
2,210 
2,270 
17,060 

4,260 

3,640 
2,740 
i  32,  430 
238,380 
233,315 
7,200 

2,730 
1,725 
5,875 
3,520 
915 

12  bolts  for  1896  Mi, 
24  for  1896  Mil. 

For  1896  Mi. 
Do. 

For  1896  Mil. 
For  1896  Mi  only. 

...do.... 
...do.... 
Loose... 

Box  

Crates  .  . 
do 

•Vzimuth  circle  sections 

Azimuth  circle  sections,  with  ]  6  angles  for  platform. 
Base  ring,  traversing  rack,  and  tap  bolts 

Counter-recoil  springs  (20  small,  20  large),  with 
5  spring  guide  rods  and  10  nuts  for  spring  guide 
rods. 
Distance  ring  sections  (each  crate  1,820  pounds)  .  .  . 
Floor  plates  (each  crate  685  pounds)  
Racer  

Loose... 
...do.... 

Side  frames,  with  2  cap  squares  (each  frame  3,600 
pounds). 
Spring  box  brackets  

Box..   . 
...do..  . 
Loose.  . 
Boxes   . 
Box..   . 

Spring  box 

Top  carriage,  complete  

Traversing  rollers  (each  box  880  pounds) 

Traversing  shaft  pedestal,  with  cover,  8  cover 
screws  a:id  worm  wheel. 

1  Cast  iron. 


2  Cast  steel. 


Weight  of  largest  package  in  which  remaining  parts  of  carriages  are  shipped  is  2.500  pounds. 
Total  weights  of  carriages  prepared  for  shipment: 
Model  of  1896  Mi— 

With  cast-iron  racer 

With  cast-steel  racer 

Model  of  1896  Mn... 


Pounds. 


102,  725 
90,  718 


WAR  DEPARTMENT, 

OFFICE  OF  THE  CHIEF  OF  ORDNANCE, 

Washington,  January  11,  1916. 

Apr.  22,  1909. 
Revised  March  18,  1913. 
Revised  January  11,  1916. 
Form  No.  1705. 
Ed.  Aug.  24-17—500. 


9977—17— 


rfcj 

V-^-T  *i;aJKli'  '  KUA 


YC  64344 


3GC527 


UNIVERSITY  OF  CALIFORNIA  LIBRARY  ~ 


